Journal articles: 'Optically induced heating'

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Palermo, Giovanna, Roberto Caputo, Antonio De Luca, and Cesare Paolo Umeton. "Control of the optically induced heating of gold nanoparticles." Photonics Letters of Poland 9, no. 1 (March 31, 2017): 17. http://dx.doi.org/10.4302/plp.v9i1.706.

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Gold nanoparticles (GNPs) have proven to be good nano-sources of heat in the presence of specific electromagnetic radiation. This process, in fact, becomes strongly enhanced under plasmon resonance. In particular, the amount of generated heat and the consequent temperature increase depend on the number of GNPs that are collectively excited and on their relative distance. As a result, the regime of heat localization is deeply controlled by this last parameter. Full Text: PDF ReferencesHutter, E., and Fendler, J. H. "Exploitation of localized surface plasmon resonance". Advanced Materials 16.19, 1685-1706 (2004) CrossRef Liz-Marzán, L. M., Murphy, C. J., & Wang, J. "Nanoplasmonics". Chemical Society Reviews, 43(11), 3820-3822 (2014). CrossRef Maier, S. A. "Plasmonics: fundamentals and applications". Springer Science & Business Media (2007). CrossRef Palpant, B. "Photothermal properties of gold nanoparticles. Gold nanoparticles in physics, chemistry and biology". Imperial College Press, London, (2012). DirectLink Baffou, G. and Quidant R. "Thermo-plasmonics: using metallic nanostructures as nanosources of heat". Laser & Photonics Reviews, 7(2):171?187, (2013). CrossRef Pelton, M., Aizpurua, J., & Bryant, G. "Metal?nanoparticle plasmonics". Laser & Photonics Reviews, 2(3), 136-159 (2008). CrossRef Kreibig, U., & Vollmer, M. "Optical properties of metal clusters" (Vol. 25). Springer Science & Business Media (2013). DirectLink J., Prashant K., S. Eustis, and M. A. El-Sayed. "Plasmon coupling in nanorod assemblies: optical absorption, discrete dipole approximation simulation, and exciton-coupling model." The Journal of Physical Chemistry B 110 (37) 18243-18253 (2006). CrossRef Jain, P. K., & El-Sayed, M. A. "Surface plasmon coupling and its universal size scaling in metal nanostructures of complex geometry: elongated particle pairs and nanosphere trimmers". The Journal of Physical Chemistry C, 112(13), 4954-4960 (2008). CrossRef Chapuis, P. O., Laroche, M., Volz, S., & Greffet, J. J. "Radiative heat transfer between metallic nanoparticles". Applied Physics Letters, 92(20), 201906 (2008). CrossRef Jain, P. K., & El-Sayed, M. A. "Plasmonic coupling in noble metal nanostructures". Chemical Physics Letters, 487(4), 153-164 (2010). CrossRef Cataldi, U., Caputo, R., Kurylyak, Y., Klein, G., Chekini, M. Cesare Umeton, C., Bürgi, T. "Growing gold nanoparticles on a flexible substrate to enable simple mechanical control of their plasmonic coupling". J. Mater. Chem. C, 2, 7927-7933 (2014). CrossRef

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Palermo, Giovanna, Rossella Grillo, Luigia Pezzi, Thomas Bürgi, Nelson Tabiryan, Luciano De Sio, and Cesare Umeton. "Photo-Aligned Nematic Liquid Crystals Enable the Modulation of Thermoplasmonic Heating." Applied Sciences 11, no. 14 (July 7, 2021): 6272. http://dx.doi.org/10.3390/app11146272.

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We experimentally demonstrate that the plasmonic heat delivered by a single layer of homogeneously distributed gold nanoparticles (AuNPs), immobilized on a glass substrate, can be optically tuned by taking advantage of the properties of an organic layer based on azobenzene and nematic liquid crystal (NLC) molecules. The effect, which exploits the dependence of the NLC refractive index value on the molecular director orientation, is realized using the polarization-dependent, light-induced molecular reorientation of a thin film of photo-aligning material that the NLC is in contact with. The reversibility of the optically induced molecular director reorientation of the NLC enables an active modulation of the plasmonic photo-induced heat.

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Kiefersauer, Reiner, Brigitte Grandl, Stephan Krapp, and Robert Huber. "IR laser-induced protein crystal transformation." Acta Crystallographica Section D Biological Crystallography 70, no. 5 (April 26, 2014): 1224–32. http://dx.doi.org/10.1107/s1399004714002223.

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A method and the design of instrumentation, and its preliminary practical realisation, including test experiments, with the object of inducing phase changes of biomolecular crystals by controlled dehydration through heating with infrared (IR) light are described. The aim is to generate and select crystalline phases through transformation in the solid state which have improved order (higher resolution in X-ray diffraction experiments) and reduced mosaic spread (more uniformly aligned mosaic blocks) for diffraction data collection and analysis. The crystal is heated by pulsed and/or constant IR laser irradiation. Loss of crystal water following heating and its reabsorption through equilibration with the environment is measured optically by a video system. Heating proved superior to traditional controlled dehydration by humidity change for the test cases CODH (carbon monoxide dehydrogenase) and CLK2 (a protein kinase). Heating with IR light is experimentally simple and offers an exploration of a much broader parameter space than the traditional method, as it allows the option of varying the rate of phase changes through modification of the IR pulse strength, width and repeat frequency. It impacts the crystal instantaneously, isotropically and homogeneously, and is therefore expected to cause less mechanical stress.

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WOOLARD, DWIGHT, WEIDONG ZHANG, ELLIOTT BROWN, BORIS GELMONT, and ROBERT TREW. "AN OPTICALLY-TRIGGERED I-RTD HYBRID THz OSCILLATOR DESIGN." International Journal of High Speed Electronics and Systems 17, no. 02 (June 2007): 339–53. http://dx.doi.org/10.1142/s0129156407004540.

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A design and analysis study is presented for a new optically-triggered (OT) interband resonant-tunneling-diode (I-RTD) device that has potential for generating terahertz (THz) frequency oscillations and achieving enhanced output power levels under pulsed operation. The proposed device utilizes novel nanoscale mechanisms to achieve externally driven oscillations that consist of two phases – i.e., an initial transient phase produced by a natural Zener (interband) tunneling process and a second discharging transient phase induced by optical annihilation of stored hole-charge by externally-injected photon flux. The specific focus of this paper will be on an OT-I-RTD oscillator that utilizes In 1- x Ga x As / GaSb y As 1- y hetero-systems and the application of band-engineering to enable triggering by 1.55 μm laser technology. The paper presents performance results for the hybrid circuit design, along with a practical implementation strategy for integrating the optical triggering and an analysis of the heating induced during large signal operation.

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Fukushima, Toshiyuki, Kiyohiro Takachi, and Kenji Tsuchihara. "Optically Active Poly(phenylacetylene) Film: Chirality Inversion Induced by Solvent Vapor and Heating." Macromolecules 41, no. 18 (September 23, 2008): 6599–601. http://dx.doi.org/10.1021/ma8014849.

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Hu, Po-Sheng, Natalia Tomasovicova, Hsiu-Jen Chou, Meng-Chang Li, Marek Vojtko, Katarina Zakutanska, Jozefina Majorosova, Shean-Jen Chen, and Peter Kopcansky. "Hyperthermia Induced by Near-Infrared Laser-Irradiated CsWO3 Nanoparticles Disintegrates Preformed Lysozyme Amyloid Fibrils." Nanomaterials 10, no. 3 (February 29, 2020): 442. http://dx.doi.org/10.3390/nano10030442.

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This research study attempts to prove the concept of the applicability of hyperthermia to treating the lysozyme amyloid fibrils (LAFs)’s self-assembled fibrillary aggregates by a feedback-modulated temperature controller ranging from 26 °C to 80 °C, and separately, by near-infrared (NIR) laser-irradiated cesium tungstate (CsWO3) nanoparticle (NPs). The dependence of the final morphology of the amyloidal assembly on external heating and the photothermal effect of the NPs on treating the fibrillary assembly were investigated and analyzed. Experimentally, atomic force microscopy (AFM), optical stereoscopy, and scanning electron microscopy (SEM) were used primarily to ensure mutual interaction between LAFs and NPs, optically elucidate the surface contour and final fibrillary assembly upon the influence of thermal treatment, and further reveal fine-details of the optical samples. Finally, conclusive remarks are drawn that the fibrillary structures doped with the NPs exhibit an increasing degree of unique orthogonality. As the temperature rises, utter deformation of the dendritic structures of fibrillary assemblies at 70 °C was found, and NIR laser-irradiated CsWO3 NPs have been demonstrated to be useful in topically destructing pre-assembled LAFs, which may be conducive to the future development of neurodegenerative therapeutic techniques.

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Ding, Tao, Ventsislav K. Valev, Andrew R. Salmon, Chris J. Forman, Stoyan K. Smoukov, Oren A. Scherman, Daan Frenkel, and Jeremy J. Baumberg. "Light-induced actuating nanotransducers." Proceedings of the National Academy of Sciences 113, no. 20 (May 2, 2016): 5503–7. http://dx.doi.org/10.1073/pnas.1524209113.

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Nanoactuators and nanomachines have long been sought after, but key bottlenecks remain. Forces at submicrometer scales are weak and slow, control is hard to achieve, and power cannot be reliably supplied. Despite the increasing complexity of nanodevices such as DNA origami and molecular machines, rapid mechanical operations are not yet possible. Here, we bind temperature-responsive polymers to charged Au nanoparticles, storing elastic energy that can be rapidly released under light control for repeatable isotropic nanoactuation. Optically heating above a critical temperature Tc = 32 °C using plasmonic absorption of an incident laser causes the coatings to expel water and collapse within a microsecond to the nanoscale, millions of times faster than the base polymer. This triggers a controllable number of nanoparticles to tightly bind in clusters. Surprisingly, by cooling below Tc their strong van der Waals attraction is overcome as the polymer expands, exerting nanoscale forces of several nN. This large force depends on van der Waals attractions between Au cores being very large in the collapsed polymer state, setting up a tightly compressed polymer spring which can be triggered into the inflated state. Our insights lead toward rational design of diverse colloidal nanomachines.

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Stergar, Jošt, and Natan Osterman. "Thermophoretic tweezers for single nanoparticle manipulation." Beilstein Journal of Nanotechnology 11 (July 30, 2020): 1126–33. http://dx.doi.org/10.3762/bjnano.11.97.

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We present the trapping and manipulation of a single nano-object in an aqueous medium by optically induced temporally varying temperature gradients. By real-time object tracking and control of the position of the heating laser focus, we can precisely employ thermophoretic drift to oppose the random diffusive motion. As a result, a nano-object is confined in a micrometer-sized trap. Numerical modeling gives a quantitative prediction of the effect. Traps can be dynamically created and relocated, which we demonstrate by the controlled independent manipulation of two nanoparticles.

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Drobczyński, Sławomir, Katarzyna Prorok, Konstantin Tamarov, Kamila Duś-Szachniewicz, Vesa-Pekka Lehto, and Artur Bednarkiewicz. "Toward Controlled Photothermal Treatment of Single Cell: Optically Induced Heating and Remote Temperature Monitoring In Vitro through Double Wavelength Optical Tweezers." ACS Photonics 4, no. 8 (July 18, 2017): 1993–2002. http://dx.doi.org/10.1021/acsphotonics.7b00375.

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Arras, Phil, and Nevin N. Weinberg. "Urca reactions during neutron star inspiral." Monthly Notices of the Royal Astronomical Society 486, no. 1 (March 28, 2019): 1424–36. http://dx.doi.org/10.1093/mnras/stz880.

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Abstract We study the impact of Urca reactions driven by tidally induced fluid motion during binary neutron star inspiral. Fluid compression is computed for low radial order oscillation modes through an adiabatic, time-dependent solution for the mode amplitudes. Optically thin neutrino emission and heating rates are then computed from this adiabatic fluid motion. Calculations use direct and modified Urca reactions operating in a $M=1.4\, \mathrm{ M}_\odot$ neutron star, which is constructed using the Skyrme Rs equation of state. We find that the energy pumped into low-order oscillation modes is not efficiently thermalized even by direct Urca reactions, with core temperatures reaching only T ≃ 108 K during the inspiral. Although this is an order of magnitude larger than the heating due to shear viscosity considered by previous studies, it reinforces the result that the stars are quite cold at merger. Upon excitation of the lowest order g mode, the chemical potential imbalance reaches $\beta \gtrsim 1\, \rm MeV$ at orbital frequencies $\nu _{\rm orb} \gtrsim 200\, \rm Hz$, implying significant charged-current optical depths and Fermi-blocking. To assess the importance of neutrino degeneracy effects, the neutrino transfer equation is solved in the static approximation for the three-dimensional density distribution, and the reaction rates are then computed including Fermi-blocking. We find that the heating rate is suppressed by a factor of a ∼2 for $\nu _{\rm orb} \gtrsim 200\, \rm Hz$. The spectrum of emitted νe and $\bar{\nu }_e$, including radiation transfer effects, is presented for a range of orbital separations.

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Utochkin, Vladimir V., Konstantin E. Kudryavtsev, Alexander A. Dubinov, Mikhail A. Fadeev, Vladimir V. Rumyantsev, Anna A. Razova, Egor V. Andronov, et al. "Stimulated Emission up to 2.75 µm from HgCdTe/CdHgTe QW Structure at Room Temperature." Nanomaterials 12, no. 15 (July 28, 2022): 2599. http://dx.doi.org/10.3390/nano12152599.

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Heterostructures with thin Hg(Cd)Te/CdHgTe quantum wells (QWs) are attractive for the development of mid-infrared interband lasers. Of particular interest are room-temperature operating emitters for the short-wavelength infrared range (SWIR, typically defined as 1.7–3 μm). In this work, we report on the observation of stimulated emission (SE) in the 2.65–2.75 µm wavelength range at room temperature in an optically pumped HgCdTe QW laser heterostructure. We study a series of three samples with lengths ranging from 2.5 to 7 mm and discuss the effects related to the non-uniformity of the excitation beam profile. SE threshold intensity and the magnitude of pump-induced carrier heating are found to be effectively dependent on the chip size, which should be accounted for in possible designs of HgCdTe-based optical converters. We also pay attention to the problem of active medium engineering in order to push the SE wavelength towards the 3–5 µm atmospheric window and to lower the SE threshold.

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Seo, Sang-Woo, Youngsik Song, and Hojjat Rostami Azmand. "Photothermal liquid release from arrayed Au nanorod/hydrogel composites for chemical stimulation." Journal of Micromechanics and Microengineering 32, no. 1 (November 30, 2021): 015003. http://dx.doi.org/10.1088/1361-6439/ac39fa.

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Abstract Controlled photothermal actuation of liquid release is presented using periodically arrayed hydrogel columns in a macroporous silicon membrane. Thermo-responsive hydrogel is mixed with Gold (Au) nanorods, and surface plasmon-induced local heating by near-infrared (NIR) light is utilized as an actuation method. We adopted theoretical modeling, which treats the hydrogel as a poro-viscoelastic medium to understand the mechanical and liquid transport properties of the hydrogel. To demonstrate the feasibility of the liquid release control using NIR light, we first characterized the temperature response of Au nanorod embedded hydrogel in the silicon membrane using its optical transmission behavior to confirm the successful device fabrication. Next, the liquid release characteristics from the structure were studied using fluorescent imaging of fluorescein dye solution while pulsed NIR light was illuminated on the structure. We successfully demonstrate that the liquid release can be controlled using remote NIR illumination from the presented structure. Considering the periodically arrayed configuration with high spatial resolution, this will have a potential prospect for optically-addressable chemical release systems, which benefit retina prosthesis interfaces.

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Hossain, Mohammad A., Ahsan Choudhuri, and Norman Love. "Design of an optically accessible turbulent combustion system." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 1 (February 8, 2018): 336–49. http://dx.doi.org/10.1177/0954406218757565.

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In order to design the next generation of gas turbine combustors and rocket engines, understanding the flame structure at high-intensity turbulent flows is necessary. Many experimental studies have focused on flame structures at relatively low Reynolds and Damköhler numbers, which are useful but do not help to provide a deep understanding of flame behavior at gas turbine and rocket engine operating conditions. The current work is focused on the presentation of the design and development of a high-intensity (Tu = 15–30%) turbulent combustion system, which is operated at compressible flow regime from Mach numbers of 0.3 to 0.5, preheated temperatures up to 500 K, and premixed conditions in order to investigate the flame structure at high Reynolds and Damköhler numbers in the so-called thickened flame regime. The design of an optically accessible backward-facing step stabilized combustor was designed for a maximum operating pressure of 0.6 MPa. Turbulence generator grid was introduced with different blockage ratios from 54 to 67% to generate turbulence inside the combustor. Optical access was provided via quartz windows on three sides of the combustion chamber. Extensive finite element analysis was performed to verify the structural integrity of the combustor at rated conditions. In order to increase the inlet temperature of the air, a heating section is designed and presented in this paper. Separate cooling subsystem designs are also presented. A 10 kHz time-resolved particle image velocimetry system and a 3 kHz planer laser-induced fluorescence system are integrated with the system to diagnose the flow field and the flame, respectively. The combustor utilizes a UNS 316 stainless steel with a minimum wall thickness of 12.5 mm. Quartz windows were designed with a maximum thickness of 25.4 mm resulting in an overall factor of safety of 3.5.

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Калашникова, А. М., Н. Е. Хохлов, Л. А. Шелухин, and А. В. Щербаков. "Сверхбыстрое лазерно-индуцированное управление магнитной анизотропией наноструктур." Журнал технической физики 91, no. 12 (2021): 1848. http://dx.doi.org/10.21883/jtf.2021.12.51751.228-21.

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Employing short laser pulses with a duration below 100 fs for changing magnetic state of magnetically-ordered media has developed into a distinct branch of magnetism —femtomagnetism which aims at controlling magnetization at ultimately short timescales. Among plethora of femtomagnetic phenomena, there is a class related to impact of femtosecond pulses on magnetic anisotropy of materials and nanostructures which defines orientation of magnetization, magnetic resonance frequencies and spin waves propagation. We present a review of main experimental results obtained in this field. We consider basic mechanisms responsible for a laser-induced change of various anisotropy types: magnetocrystalline, magnetoelastic, interfacial, shape anisotropy, and discuss specifics of these processes in magnetic metals and dielectrics. We consider several examples and describe features of magnetic anisotropy changes resulting from ultrafast laser-induced heating, impact of laser-induced dynamic and quasistatic strains and resonant excitation of electronic states. We also discuss perspectives of employing various mechanisms of laser-induced magnetic anisotropy change for enabling processes prospective for developing devices. We consider precessional magnetization switching for opto-magnetic information recording, generation of high-frequency strongly localized magnetic excitations and fields for magnetic nanotomography and hybrid magnonics, as well as controlling spin waves propagation for optically-reconfigurable magnonics. We further discuss opportunities which open up in studies of ultrafast magnetic anisotropy changes because of using short laser pulses in infrared and terahertz ranges.

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ELIM, HENDRY IZAAC, WEIZHE CHEN, WEI JI, ZIYI ZHONG, JIANYI LIN, GWEE CHEN MENG, K. C. CHIN, et al. "OPTICAL LIMITING STUDIES OF NEW CARBON NANOCOMPOSITES AND AMORPHOUS SixNy OR AMORPHOUS SiC COATED MULTI-WALLED CARBON NANOTUBES." Journal of Nonlinear Optical Physics & Materials 13, no. 02 (June 2004): 275–89. http://dx.doi.org/10.1142/s0218863504001876.

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By using fluence-dependent transmission measurement with nanosecond laser pulses, we have studied optical limiting (OL) properties of new carbon nanocomposites as well as amorphous Si x N y or amorphous SiC coated carbon nanotubes suspended in distilled water. The observed nonlinearity at 532 nm contributed to OL performance of the carbon nanocomposites or carbon nanoballs (CNBs) is suggested to have its origin in the optically induced heating or scattering effects. It is found that when the linear transmittance of the CNBs is less than or equal to 70%, the intensity-dependent transmission of the CNBs is comparable to that of C 60. While at 80% linear transmittance, CNBs possess better OL behavior than that of C 60. These findings strongly support a potential application of CNBs for all laser protection devices. We have also observed OL effects in the amorphous silicon nitride ( a - Si x N y) and amorphous silicon carbide ( a - SiC ) coated multi-walled carbon nanotubes (MWNTs) at wavelengths of 532 and 1064 nm, and found that their OL performances are slightly poorer than that of their parent MWNTs. The possible sources of thickness-dependent OL effects of a - Si x N y and a - SiC coated MWNTs are discussed.

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ASHKINADZE, B. M., E. LINDER, E. COHEN, and L. N. PFEIFFER. "MICROWAVE-MODULATED PHOTOLUMINESCENCE OF A TWO-DIMENSIONAL ELECTRON GAS." International Journal of Modern Physics B 21, no. 08n09 (April 10, 2007): 1541–48. http://dx.doi.org/10.1142/s0217979207043166.

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The primary effect of microwave (mw) irradiation on a two dimensional electron gas (2DEG) is heating due to mw absorption by the electrons. At low lattice temperatures, pronounced secondary effects are observed: mw-induced modification of the photoluminescence (PL) spectrum and mw-induced resistance oscillations (MIRO). We present an experimental study of mw-modulated PL (MPL) spectroscopy in modulation-doped GaAs/AlGaAs QW's At low magnetic field strengths (B < 0.5 T ), the analysis of the MPL spectra indicates that they arise of a redistribution of the photoexcited holes within the energy states of the top valence band. This is caused by absorbing low-energy acoustic phonons that are emitted by the mw-heated 2DEG. We propose that these nonequilibrium phonons also affect the 2DEG mobility leading to the MIRO's. For B > 0.5 T and intense mw-irradiation, new optically detected resonances (ODRs) are observed at magnetic fields that depend on the 2DEG density and approximately correspond to integer electron filling factors. We argue that these resonances result from a slight 2DEG density increase under mw irradiation with a concurent, low-energy PL spectral shift due to a small bandgap narrowing.

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Paul, Ashish. "Transient Free Convective MHD Flow Past an Exponentially Accelerated Vertical Porous Plate with Variable Temperature through a Porous Medium." International Journal of Engineering Mathematics 2017 (January 17, 2017): 1–9. http://dx.doi.org/10.1155/2017/2981071.

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This paper is concerned with analytical solution of one-dimensional unsteady laminar boundary layer MHD flow of a viscous incompressible fluid past an exponentially accelerated infinite vertical plate in presence of transverse magnetic field. The vertical plate and the medium of flow are considered to be porous. The fluid is assumed to be optically thin and the magnetic Reynolds number is considered small enough to neglect the induced hydromagnetic effects. The governing boundary layer equations are first converted to dimensionless form and then solved by Laplace transform technique. Numerical values of transient velocity, temperature, skin friction, and Nusselt number are illustrated and are presented in graphs for various sets of physical parametric values, namely, Grashof number, accelerating parameter, suction parameter, permeability parameter, radiation parameter, magnetic parameter, and time. It is found that the velocity decreases with increases of the suction parameter for both cases of cooling and heating of the porous plate whereas skin friction increases with increase of suction parameter.

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Hemmer, Eva. "(Invited) Lanthanide-Based Nanoparticles Via Rapid Microwave-Assisted Synthesis and Their Application from Biomedicine to Printing." ECS Meeting Abstracts MA2022-01, no. 20 (July 7, 2022): 1097. http://dx.doi.org/10.1149/ma2022-01201097mtgabs.

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Based on their outstanding optical properties, lanthanide-based compounds have been suggested for a wide range of applications including the fields of biomedicine, optoelectronics, and solar energy conversion. For instance, the capability of lanthanide-based materials to emit visible and near-infrared (NIR) light under NIR excitation is highly sought after when aiming for biomedical applications. This is as NIR light penetrates deeper into biological tissue and is less phototoxic than UV light commonly used for optical bioprobes. Our favorite nanomaterials are lanthanide-based fluorides (MLnF4, M = alkali metal, Ln = lanthanides and Yttrium), and our research addresses challenges in their synthesis as well as the establishment of structure-property relationships. The growing attention toward such optically active materials has prompted the development of novel synthesis methods for a more reliable and efficient access to these systems. In this regard, microwave-assisted approaches provide unique advantages over traditional solvothermal methods reliant on convectional heating: namely, significantly shorter reaction durations, more rigid reaction conditions, and thus a higher degree of reproducibility. The developed approach allows to control the material’s crystalline phase and doping of various Ln3+ ions into core/shell architectures. Additional surface modification with biopolymers renders the nanomaterials dispersible in various solvents and allows for their assembly into multipurpose micro-carriers. The resultant emission color-tunable upconverting nanoparticles are promising candidates for versatile applications, ranging from multiplexed imaging and light-induced therapy to inks for printing of micropatterns for optoelectronic devices.

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Sebbe, Priscilla Fróes, Antônio Balbin Villaverde, Leonardo Marmo Moreira, Ana Maria Barbosa, and Nelson Veissid. "Characterization of a novel LEDs device prototype for neonatal jaundice and its comparison with fluorescent lamps sources: Photpublisher-idapy treatment of hyperbilirubinemia in Wistar rats." Spectroscopy 23, no. 5-6 (2009): 243–55. http://dx.doi.org/10.1155/2009/761981.

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This work describes experimental tests done using the LED-therapy equipment developed for neonatal jaundice treatment. Neonatal photpublisher-idapy consists in the irradiation of jaundice new-born with a high intensity light, in the spectral range of 400–500 nm, in order to promote the photochemical transformation of the bilirubin molecules in the areas exposed to the light. A convenient light source for jaundice treatment can be obtained employing blue LEDs, which are simple devices that present low cost, small heating production, narrow spectral band and long life-time. Equipment using an array with 88 blue LEDs (emission peak at 472 nm with 50 nm bandwidth) was constructed, optically characterized and then validated in comparison with a commercial equipment of photpublisher-idapy, i.e., the Fluorescent Conventional. For the device validation, experiments were undertaken employing male Wistar rats, to which the hyperbilirubinemia was induced by the obstruction of the billi duct. Using the LED-therapy equipment, it was obtained a reduction by 78% of the indirect bilirubin concentration against only 39% referent to the commercial Fluorescent Conventional, both for 8 h of treatment. For a period of 24 h, the reduction was 92% and 76%, respectively. Thus, the novel LED-therapy equipment was more efficient for photodegradation of the bilirubin molecules in animal model, when compared with the Conventional equipment. The novel prototype present requisites to be applied in clinical treatments, such as a large and uniform area of irradiation, efficient wavelength emission for jaundice treatment, high spectral irradiance, simplicity and low values of weight, heating and cost. Therefore, the new device is candidate to systematic applications in photpublisher-idapy treatments.

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Costantino, L., and F. M. Bréon. "Aerosol indirect effect on warm clouds over South-East Atlantic, from co-located MODIS and CALIPSO observations." Atmospheric Chemistry and Physics Discussions 12, no. 6 (June 7, 2012): 14197–246. http://dx.doi.org/10.5194/acpd-12-14197-2012.

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Abstract. In this study, we provide a comprehensive analysis of aerosol interaction with warm boundary layer clouds, over South-East Atlantic. We use MODIS retrievals to derive statistical relationships between aerosol concentration and cloud properties, together with co-located CALIPSO estimates of cloud and aerosol layer altitudes. The latter are used to differentiate between cases of mixed and interacting cloud-aerosol layers from cases where the aerosol is located well-above the cloud top. This strategy allows, to a certain extent, to isolate real aerosol-induced effect from meteorology. Similar to previous studies, statistics clearly show that aerosol affects cloud microphysics, decreasing the Cloud Droplet Radius (CDR). The same data indicate a concomitant strong decrease in cloud Liquid Water Path (LWP), in evident contrast with the hypothesis of aerosol inhibition of precipitation (Albrecht, 1989). Because of this water loss, probably due to the entrainment of dry air at cloud top, Cloud Optical Thickness (COT) is found to be almost insensitive to changes in aerosol concentration. The analysis of MODIS-CALIPSO coincidences also evidenced an aerosol enhancement of low cloud cover. Surprising, the Cloud Fraction (CLF) response to aerosol invigoration is much stronger when (absorbing) particles are located above cloud top, than in cases of physical interaction, This result suggests a relevant aerosol radiative effect on low cloud occurrence. Heating the atmosphere above the inversion, absorbing particles above cloud top may decrease the vertical temperature gradient, increase the low tropospheric stability and provide favorable conditions for low cloud formation. We also focus on the impact of anthropogenic aerosols on precipitation, through the statistical analysis of CDR-COT co-variations. A COT value of 10 is found to be the threshold beyond which precipitation mostly forms, in both clean and polluted environments. For larger COT, polluted clouds showed evidence of precipitation suppression. Results suggest the presence of two competing mechanisms governing LWP response to aerosol invigoration: a drying effect due to aerosol enhanced entrainment of dry air at cloud top (predominant for optically thin clouds) and a moistening effect due to aerosol inhibition of precipitation (predominant for optically thick clouds).

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Kosarev, N. I. "Two-step photoionization of barium atoms through excited P11,3 levels in optical dense approximation." Physica Scripta 98, no. 1 (December 19, 2022): 015406. http://dx.doi.org/10.1088/1402-4896/acaa0f.

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Abstract The kinetics of two-step photoionization of barium atoms through excited P 1 1 , 3 levels was studied by numerical simulation method in the optically dense approximation. The first laser at wavelength λ 1 = 553.5 nm ( λ 1 = 791 nm) pumps transition S 0 1 ↔ P 1 1 ( S 0 1 ↔ P 1 3 ). The second laser with λ 2 = 266 nm ( λ 2 = 310 nm) ionizes atoms from the level P 1 1 ( P 1 3 ). The third probe laser with wavelength λ i = 493.41 nm causes resonant fluorescence of barium ions. It is shown that the metastable D 2 3 from the D 1 , 2 , 3 3 triplet in barium is strongly populated through P 1 1 , 3 levels. Therefore, the applying of the ionizing laser tuned to a continuum from this metastable D 2 3 can yield a significant increase in the ionization efficiency. The laser-induced fluorescence method makes it possible to estimate the photoionization yield of barium ions with an error of up to 8%. The loading rate of the barium ion beam into the ion trap, obtained numerically, is consistent with the experimental data [Opt. Exp. 19(17), 16438 (2011)]. The deceleration of ultracold plasma recombination due to the heating of electrons in superelastic collisions for the characteristic times of a two-stage process is predicted.

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Flaccomio, E., G. Micela, S. Sciortino, A. M. Cody, M. G. Guarcello, M. Morales-Calderòn, L. Rebull, and J. R. Stauffer. "A multi-wavelength view of magnetic flaring from PMS stars." Astronomy & Astrophysics 620 (November 29, 2018): A55. http://dx.doi.org/10.1051/0004-6361/201833308.

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Context. Flaring is an ubiquitous manifestation of magnetic activity in low mass stars including, of course, the Sun. Although flares, both from the Sun and from other stars, are most prominently observed in the soft X-ray band, most of the radiated energy is released at optical/UV wavelengths. In spite of decades of investigation, the physics of flares, even solar ones, is not fully understood. Even less is known about magnetic flaring in pre-main sequence (PMS) stars, at least in part because of the lack of suitable multi-wavelength data. This is unfortunate since the energetic radiation from stellar flares, which is routinely observed to be orders of magnitude greater than in solar flares, might have a significant impact on the evolution of circumstellar, planet-forming disks. Aims. We aim at improving our understanding of flares from PMS stars. Our immediate objectives are constraining the relation between flare emission at X-ray, optical, and mid-infrared (mIR) bands, inferring properties of the optically emitting region, and looking for signatures of the interaction between flares and the circumstellar environment, i.e. disks and envelopes. This information might then serve as input for detailed models of the interaction between stellar atmospheres, circumstellar disks and proto-planets. Methods. Observations of a large sample of PMS stars in the NGC 2264 star forming region were obtained in December 2011, simultaneously with three space-borne telescopes, Chandra (X-rays), CoRoT (optical), and Spitzer (mIR), as part of the “Coordinated Synoptic Investigation of NGC 2264” (CSI-NGC 2264). Shorter Chandra and CoRoT observations were also obtained in March 2008. We analyzed the lightcurves obtained during the Chandra observations (∼300 ks and ∼60 ks in 2011 and 2008, respectively), to detect X-ray flares with an optical and/or mIR counterpart. From the three datasets we then estimated basic flare properties, such as emitted energies and peak luminosities. These were then compared to constrain the spectral energy distribution of the flaring emission and the physical conditions of the emitting regions. The properties of flares from stars with and without circumstellar disks were also compared to establish any difference that might be attributed to the presence of disks. Results. Seventy-eight X-ray flares (from 65 stars) with an optical and/or mIR counterpart were detected. The optical emission of flares (both emitted energy and peak flux) is found to correlate well with, and to be significantly larger than, the X-ray emission. The slopes of the correlations suggest that the difference becomes smaller for the most powerful flares. The mIR flare emission seems to be strongly affected by the presence of a circumstellar disk: flares from stars with disks have a stronger mIR emission with respect to stars without disks. This might be attributed to either a cooler temperature of the region emitting both the optical and mIR flux or, perhaps more likely, to the reprocessing of the optical (and X-ray) flare emission by the inner circumstellar disk, providing evidence for flare-induced disk heating.

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Peterman, Erwin J. G., Frederick Gittes, and Christoph F. Schmidt. "Laser-Induced Heating in Optical Traps." Biophysical Journal 84, no. 2 (February 2003): 1308–16. http://dx.doi.org/10.1016/s0006-3495(03)74946-7.

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Tsoulos, Ted V., and Giulia Tagliabue. "Self-induced thermo-optical effects in silicon and germanium dielectric nanoresonators." Nanophotonics 9, no. 12 (April 18, 2020): 3849–61. http://dx.doi.org/10.1515/nanoph-2019-0534.

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AbstractDielectric nanoresonators uniquely support both magnetic and electric resonances across a wide wavelength range. They are thus being exploited in a growing number of groundbreaking applications. In particular, they have been recently suggested as promising nanoheaters. However, while the thermo-optical properties of silicon and germanium resonators have been exploited to realize tunable metasurfaces based on external thermal inputs, the effect of self-induced optical heating onto their resonances has so far been neglected. In this study, we address the problem of self-heating of a thermo-optical resonator. In particular, employing a recursive procedure to account for the interdependence between the absorption cross section and the temperature of the resonator, we show that self-heating gives rise to a complex, nonlinear relationship between illumination intensity and temperature. Using both analytical and numerical models, we also observe that self-induced optical heating has nonnegligible effects on the spectral position of electric and magnetic resonances of spheres as well as anapole modes of nanodisks, even for moderate illumination intensities relevant for applications such as Raman scattering. Thus, our work demonstrates that self-induced optical heating must be properly accounted for when designing dielectric resonators for a wide range of devices.

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Taranenko, Y. N., U. S. Inan, and T. F. Bell. "Optical signatures of lightning-Induced heating of theDregion." Geophysical Research Letters 19, no. 18 (September 23, 1992): 1815–18. http://dx.doi.org/10.1029/92gl02106.

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Xia, Jinjun, Amanda Weaver, David E. Gerrard, and Gang Yao. "Heating induced optical property changes in beef muscle." Journal of Food Engineering 84, no. 1 (January 2008): 75–81. http://dx.doi.org/10.1016/j.jfoodeng.2007.04.023.

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Chen, G., and C. L. Tien. "Thermally Induced Optical Nonlinearity During Transient Heating of Thin Films." Journal of Heat Transfer 116, no. 2 (May 1, 1994): 311–16. http://dx.doi.org/10.1115/1.2911401.

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This work studies the temperature field and the optical response of weakly absorbing thin films with thermally induced optical nonlinearity during picosecond to nanosecond pulsed-laser heating. A one-dimensional model is presented that examines the effects of the temperature dependent optical constants and the nonuniform absorption caused by interference. The energy equation is solved numerically, coupled with the matrix method in optical multilayer theory. Both cadmium sulfide (CdS) thin films and a zinc selenide (ZnSe) interference filter are considered. The computational results compare favorably with available experimental data on the ZnSe interference filter. This study shows that the transient temperature distributions in the films are highly nonuniform. Such nonuniformity yields Airy’s formulae for calculating the thin-film reflectance and transmittance inapplicable. Applications of the work include optical bistability, localized change of the film structure, and measurement of the thermal diffusivity of thin films.

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Wang, Yimeng, Xinping Zhang, and Xiaohui Fang. "Ultrafast Optical Heating Induced Polarization-Dependent Optical Switching in Gold Nanowires." Applied Sciences 7, no. 1 (January 12, 2017): 46. http://dx.doi.org/10.3390/app7010046.

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Wang, C. Y., T. F. Morse, and J. W. Cipolla. "Laser-Induced Natural Convection and Thermophoresis." Journal of Heat Transfer 107, no. 1 (February 1, 1985): 161–67. http://dx.doi.org/10.1115/1.3247373.

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The influence of axial laser volumetric heating and forced convection on the motion of aerosol particles in a vertical tube has been studied using the Boussinesq approximation. For constant wall temperature, an asymptotic case provides simple temperature and velocity profiles that determine the convection and thermophoretic motion of small aerosol particles. Laser heating induces upward buoyant motion near the tube center, and when forced convection is downward, there may be an inflection in the velocity profile. For constant laser heating (a small absorption limit), a velocity profile may be found that will minimize the distance over which particles are deposited on the wall. Such an observation may have some bearing on the manufacture of preforms from which optical fibers are drawn.

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Fu, Wang, Liu, Bai, Liao, He, and Wang. "Recent Progress in Fabrications and Applications of Heating-Induced Long Period Fiber Gratings." Sensors 19, no. 20 (October 15, 2019): 4473. http://dx.doi.org/10.3390/s19204473.

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This paper presents a review of our work concerning the recent progress in fabrications and applications of heating-induced long period fiber gratings (LPFGs). Firstly, three kinds of heating fabrication techniques based on CO2 laser, hydrogen–oxygen flame and arc discharge are demonstrated to fabricate LPFGs, i.e., standard LPFGs (SLPFGs) and helical LPFGs (HLPFGs), in different types of optical fibers such as conventional fibers, photonic crystal fibers, and photonic bandgap fibers. Secondly, the all-fiber orbital angular momentum (OAM) mode converters based on heating-induced SLPFGs and HLPFGs in different types of fibers are studied to increase the transmission capacity. Finally, the heating-induced SLPFGs and HLPFGs are investigated to develop various LPFG-based strain, pressure, torsion and biochemical sensors.

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Suleimanov, V. F., J. Poutanen, and K. Werner. "Accretion heated atmospheres of X-ray bursting neutron stars." Astronomy & Astrophysics 619 (November 2018): A114. http://dx.doi.org/10.1051/0004-6361/201833581.

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Some thermonuclear (type I) X-ray bursts at the neutron star surfaces in low-mass X-ray binaries take place during hard persistent states of the systems. Spectral evolution of these bursts is well described by the atmosphere model of a passively cooling neutron star when the burst luminosity is high enough. The observed spectral evolution deviates from the model predictions when the burst luminosity drops below a critical value of 20–70% of the maximum luminosity. The amplitude of the deviations and the critical luminosity correlate with the persistent luminosity, which leads us to suggest that these deviations are induced by the additional heating of the accreted particles. We present a method for computation of the neutron star atmosphere models heated by accreted particles assuming that their energy is released via Coulomb interactions with electrons. We computed the temperature structures and the emergent spectra of the atmospheres of various chemical compositions and investigate the dependence of the results on the velocity of accreted particles, their temperature and the penetration angle. We show that the heated atmosphere develops two different regions. The upper one is the hot (20–100 keV) corona-like surface layer cooled by Compton scattering, and the deeper, almost isothermal optically thick region with a temperature of a few keV. The emergent spectra correspondingly have two components: a blackbody with the temperature close to that of the isothermal region and a hard Comptonized component (a power law with an exponential decay). Their relative contribution depends on the ratio of the energy dissipation rate of the accreted particles to the intrinsic flux from the neutron star surface. These spectra deviate strongly from those of undisturbed, passively cooling neutron star atmospheres, with the main differences being the presence of a high-energy tail and a strong excess in the low-energy part of the spectrum. They also lack the iron absorption edge, which is visible in the spectra of undisturbed low-luminosity atmospheres with solar chemical composition. Using the computed spectra, we obtained the dependences of the dilution and color-correction factors as functions of relative luminosities for pure helium and solar abundance atmospheres. We show that the helium model atmosphere heated by accretion corresponding to 5% of the Eddington luminosity describes well the late stages of the X-ray bursts in 4U 1820−30.

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Ebbesen, Christian L., and Henrik Bruus. "Analysis of laser-induced heating in optical neuronal guidance." Journal of Neuroscience Methods 209, no. 1 (July 2012): 168–77. http://dx.doi.org/10.1016/j.jneumeth.2012.02.006.

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Ma, Jinyong, Jiayi Qin, Geoff T. Campbell, Ruvi Lecamwasam, Kabilan Sripathy, Joe Hope, Ben C. Buchler, and Ping Koy Lam. "Photothermally induced transparency." Science Advances 6, no. 8 (February 2020): eaax8256. http://dx.doi.org/10.1126/sciadv.aax8256.

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Induced transparency is a common but remarkable effect in optics. It occurs when a strong driving field is used to render an otherwise opaque material transparent. The effect is known as electromagnetically induced transparency in atomic media and optomechanically induced transparency in systems that consist of coupled optical and mechanical resonators. In this work, we introduce the concept of photothermally induced transparency (PTIT). It happens when an optical resonator exhibits nonlinear behavior due to optical heating of the resonator or its mirrors. Similar to the established mechanisms for induced transparency, PTIT can suppress the coupling between an optical resonator and a traveling optical field. We further show that the dispersion of the resonator can be modified to exhibit slow or fast light. Because of the relatively slow thermal response, we observe the bandwidth of the PTIT to be 2π × 15.9 Hz, which theoretically suggests a group velocity of as low as 5 m/s.

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Grigoriev, Fedor Vasilievich, Vladimir Borisovich Sulimov, and Alexander Vladimirovich Tikhonravov. "Molecular Dynamics Simulation of Laser Induced Heating of Silicon Dioxide Thin Films." Nanomaterials 11, no. 11 (November 6, 2021): 2986. http://dx.doi.org/10.3390/nano11112986.

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The full-atomistic classical molecular dynamics simulation of the laser heating of silicon dioxide thin films is performed. Both dense isotropic films and porous anisotropic films are investigated. It is assumed that heating occurs due to nodal structural defects, which are currently considered one of the possible causes of laser induced damage. It is revealed that heating to a temperature of 1000 K insignificantly affects the structure of the films and the concentration of point defects responsible for the radiation absorption. An increase in the heating temperature to 2000 K leads to the growth of the concentration of these defects. For “as deposited” films, this growth is greater in the case of a porous film deposited at a high deposition angle. Annealing of film reduces the difference in the concentration of laser induced defects in dense and porous films. The possible influence of optical active defects arising due to heating on the laser induced damage threshold is discussed.

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Graul, Jacob S., Sergey F. Gimelshein, and Taylor C. Lilly. "Numerical prediction of optical lattice-induced gas heating within multipass optical cavities." Applied Physics B 117, no. 1 (May 5, 2014): 353–61. http://dx.doi.org/10.1007/s00340-014-5842-x.

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Paz-Buclatin, Franzette, Ylenia Perera-Suárez, Inocencio R. Martín, Susana Ríos, Omar de Varona, Airán Ródenas, and Leopoldo L. Martin. "Experimental and Numerical Validation of Whispering Gallery Resonators as Optical Temperature Sensors." Sensors 22, no. 20 (October 15, 2022): 7831. http://dx.doi.org/10.3390/s22207831.

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This study experimentally and numerically validates the commonly employed technique of laser-induced heating of a material in optical temperature sensing studies. Furthermore, the Er3+-doped glass microspheres studied in this work can be employed as remote optical temperature sensors. Laser-induced self-heating is a useful technique commonly employed in optical temperature sensing research when two temperature-dependent parameters can be correlated, such as in fluorescence intensity ratio vs. interferometric calibration, allowing straightforward sensor characterization. A frequent assumption in such experiments is that thermal homogeneity within the sensor volume, that is, a sound hypothesis when dealing with small volume to surface area ratio devices such as microresonators, but has never been validated. In order to address this issue, we performed a series of experiments and simulations on a microsphere supporting whispering gallery mode resonances, laser heating it at ambient pressure and medium vacuum while tracking the resonance wavelength shift and comparing it to the shift rate observed in a thermal bath. The simulations were done starting only from the material properties of the bulk glass to simulate the physical phenomena of laser heating and resonance of the microsphere glass. Despite the simplicity of the model, both measurements and simulations are in good agreement with a highly homogeneous temperature within the resonator, thus validating the laser heating technique.

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Fujimoto, Keiya, Hiroaki Hanafusa, Takuma Sato, and Seiichiro Higashi. "Direct observation of three-dimensional transient temperature distribution in SiC Schottky barrier diode under operation by optical-interference contactless thermometry imaging." Applied Physics Express 15, no. 2 (January 25, 2022): 026502. http://dx.doi.org/10.35848/1882-0786/ac4a10.

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Abstract We have developed optical-interference contactless thermometry imaging technique to visualize three-dimensional transient temperature distribution in 4H-SiC Schottky barrier diode (SBD) under operation. When a 1 ms forward pulse bias was applied, clear variation of optical interference fringes induced by self-heating and cooling were observed. Thermal diffusion and optical analysis revealed three-dimensional temperature distribution with high spatial (≤10 μm) and temporal (≤100 μs) resolutions. A hot spot that signals breakdown of the SBD was successfully captured as an anomalous interference, which indicated a local heating to a temperature as high as 805 K at the time of failure.

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38

Marui, Yukihiro, Masashi Kawaguchi, and Masamitsu Hayashi. "Optical detection of spin–orbit torque and current-induced heating." Applied Physics Express 11, no. 9 (August 20, 2018): 093001. http://dx.doi.org/10.7567/apex.11.093001.

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39

Savard, T. A., K. M. O’Hara, and J. E. Thomas. "Laser-noise-induced heating in far-off resonance optical traps." Physical Review A 56, no. 2 (August 1, 1997): R1095—R1098. http://dx.doi.org/10.1103/physreva.56.r1095.

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40

Liu, Y., D. K. Cheng, G. J. Sonek, M. W. Berns, C. F. Chapman, and B. J. Tromberg. "Evidence for localized cell heating induced by infrared optical tweezers." Biophysical Journal 68, no. 5 (May 1995): 2137–44. http://dx.doi.org/10.1016/s0006-3495(95)80396-6.

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Zhang, Haiyan, Yixuan Cui, Xiangfu Wang, and Xiaohong Yan. "Numerical modeling of laser-induced heating effect in optical thermometry." Laser Physics 30, no. 3 (February 3, 2020): 036001. http://dx.doi.org/10.1088/1555-6611/ab68e2.

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42

Canning, John, Masood Naqshbandi, Kevin Cook, and George Huyang. "Magnetic induction-induced resistive heating of optical fibers and gratings." Optics Letters 38, no. 6 (March 13, 2013): 926. http://dx.doi.org/10.1364/ol.38.000926.

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Mocanu, Mihai, Elena Mihalache, Radu-Ioachim Comăneci, Bogdan Pricop, Burak Özkal, and Leandru Gheorghe Bujoreanu. "Tensile Stress-Induced Structural Changes Associated with Martensite Transformations in Fe-Mn-Si Based Shape Memory Alloys." Materials Science Forum 907 (September 2017): 25–30. http://dx.doi.org/10.4028/www.scientific.net/msf.907.25.

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Tensile specimens, with the chemical composition Fe-28Mn-6Si-5Cr (mass. %), were obtained by ingot metallurgy, hot rolling, solution treatment (1100°C/ 5 min/ water) and spark erosion cutting. Tensile tests were performed to failure and to prescribed strains, by loading-unloading. Ultimate strain and strength increased up to 80.8 % and 1033 MPa, respectively, with decreasing the cross section of specimens’ gauge down to 2 mm2. The specimens were pre-strained by static tensile loading-unloading tests, to permanent strains as high as 60 %. This procedure aimed to stress-induce martensite, which was further analyzed, on the gauges of pre-strained specimens, by optical and scanning electron microscopy (SEM) as well as X-ray diffraction (XRD). Thermally induced reversion to austenite, of stress-induced martensite, was emphasized, during heating, by differential scanning calorimetry (DSC).

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Prisner, Lisa, Phillip Witthöft, Lan Vi Ngoc Nguyen, Thomas Tsangas, Tobias Gefken, Florentine Klaus, Christian Strelow, Tobias Kipp, and Alf Mews. "Monitoring the death of single BaF3 cells under plasmonic photothermal heating induced by ultrasmall gold nanorods." Journal of Materials Chemistry B 7, no. 22 (2019): 3582–89. http://dx.doi.org/10.1039/c8tb03135e.

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45

Henstridge, M., M. Först, E. Rowe, M. Fechner, and A. Cavalleri. "Nonlocal nonlinear phononics." Nature Physics 18, no. 4 (March 7, 2022): 457–61. http://dx.doi.org/10.1038/s41567-022-01512-3.

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AbstractNonlinear phononics relies on the resonant optical excitation of infrared-active lattice vibrations to induce targeted structural deformations in solids. This form of dynamical crystal structure design has been applied to control the functional properties of many complex solids, including magnetic materials, superconductors and ferroelectrics. However, phononics has so far been restricted to protocols in which structural deformations occur within the optically excited volume, sometimes resulting in unwanted heating. Here, we extend nonlinear phononics to propagating polaritons, spatially separating the functional response from the optical drive. We use mid-infrared optical pulses to resonantly drive a phonon at the surface of ferroelectric LiNbO3. Time-resolved stimulated Raman scattering reveals that the ferroelectric polarization is reduced over the entire 50 µm depth of the sample, far beyond the micrometre depth of the evanescent phonon field. We attribute this effect to the anharmonic coupling between the driven mode and a polariton that propagates into the material. For high excitation amplitudes, we reach a regime in which the ferroelectric polarization is reversed, as revealed by a sign change in the Raman tensor coefficients of all the polar modes.

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Gibilisco, S., G. Faraci, A. R. Pennisi, and A. Irrera. "Laser induced heating of Si nanocrystals." Journal of Non-Crystalline Solids 356, no. 37-40 (August 2010): 1948–50. http://dx.doi.org/10.1016/j.jnoncrysol.2010.05.035.

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47

Ferrari, Marco, Valentina Cettolo, and Valentina Quaresima. "Light source-detector spacing of near-infrared-based tissue oximeters and the influence of skin blood flow." Journal of Applied Physiology 100, no. 4 (April 2006): 1426–27. http://dx.doi.org/10.1152/japplphysiol.01207.2005.

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Near-infrared (NIR) spectroscopy is a noninvasive optical technique that is increasingly used to assess muscle oxygenation during exercise with the assumption that the contribution of skin blood flow to the NIR signal is minor or nonexistent. We tested this assumption in humans by monitoring forearm tissue oxygenation during selective cutaneous vasodilation induced by locally applied heat ( n = 6) or indirect whole body heating (i.e., heating subject but not area surrounding NIR probes; n = 8). Neither perturbation has been shown to cause a measurable change in muscle blood flow or metabolism. Local heating (∼41°C) caused large increases in the NIR-derived tissue oxygenation signal [before heating = 0.82 ± 0.89 optical density (OD), after heating = 18.21 ± 2.44 OD; P < 0.001]. Similarly, whole body heating (increase internal temperature 0.9°C) also caused large increases in the tissue oxygenation signal (before heating = −0.31 ± 1.47 OD, after heating = 12.48 ± 1.82 OD; P < 0.001). These increases in the tissue oxygenation signal were closely correlated with increases in skin blood flow during both local heating (mean r = 0.95 ± 0.02) and whole body heating (mean r = 0.89 ± 0.04). These data suggest that the contribution of skin blood flow to NIR measurements of tissue oxygenation can be significant, potentially confounding interpretation of the NIR-derived signal during conditions where both skin and muscle blood flows are elevated concomitantly (e.g., high-intensity and/or prolonged exercise).

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Davis, Scott L., Paul J. Fadel, Jian Cui, Gail D. Thomas, and Craig G. Crandall. "Skin blood flow influences near-infrared spectroscopy-derived measurements of tissue oxygenation during heat stress." Journal of Applied Physiology 100, no. 1 (January 2006): 221–24. http://dx.doi.org/10.1152/japplphysiol.00867.2005.

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Near-infrared (NIR) spectroscopy is a noninvasive optical technique that is increasingly used to assess muscle oxygenation during exercise with the assumption that the contribution of skin blood flow to the NIR signal is minor or nonexistent. We tested this assumption in humans by monitoring forearm tissue oxygenation during selective cutaneous vasodilation induced by locally applied heat ( n = 6) or indirect whole body heating (i.e., heating subject but not area surrounding NIR probes; n = 8). Neither perturbation has been shown to cause a measurable change in muscle blood flow or metabolism. Local heating (∼41°C) caused large increases in the NIR-derived tissue oxygenation signal [before heating = 0.82 ± 0.89 optical density (OD), after heating = 18.21 ± 2.44 OD; P < 0.001]. Similarly, whole body heating (increase internal temperature 0.9°C) also caused large increases in the tissue oxygenation signal (before heating = −0.31 ± 1.47 OD, after heating = 12.48 ± 1.82 OD; P < 0.001). These increases in the tissue oxygenation signal were closely correlated with increases in skin blood flow during both local heating (mean r = 0.95 ± 0.02) and whole body heating (mean r = 0.89 ± 0.04). These data suggest that the contribution of skin blood flow to NIR measurements of tissue oxygenation can be significant, potentially confounding interpretation of the NIR-derived signal during conditions where both skin and muscle blood flows are elevated concomitantly (e.g., high-intensity and/or prolonged exercise).

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Vallini, F., L. A. M. Barea, E. F. Dos Reis, A. A. Von Zuben, and N. C. Frateschi. "Induced Optical Losses in Optoelectronic Devices due Focused Ion Beam Damages." Journal of Integrated Circuits and Systems 7, no. 2 (December 27, 2012): 87–91. http://dx.doi.org/10.29292/jics.v7i2.359.

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A study of damages caused by gallium focused ion beam (FIB) into III-V compounds is presented. Potential damages caused by local heating, ion implantation, and selective sputtering are presented. Preliminary analyzes shows that local heating is negligible. Gallium implantation is shown to occur over areas tens of nanometers thick. Gallium accumulation as well as selective sputtering during III-V compounds milling is expected. Particularly, for GaAs, this effect leads to gallium segregation and formation of metallic clusters. Microdisks resonators are fabricated using FIB milling with different emission currents to analyze these effects on a device. It is shown that for higher emission current, thus higher implantation doses, the cavity quality factor rapidly decreases due optical scattering losses induced by implanted gallium atoms.

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Nigoghossian, K., S. Ouellet, J. Plain, Y. Messaddeq, D. Boudreau, and S. J. L. Ribeiro. "Upconversion nanoparticle-decorated gold nanoshells for near-infrared induced heating and thermometry." Journal of Materials Chemistry B 5, no. 34 (2017): 7109–17. http://dx.doi.org/10.1039/c7tb01621b.

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The present work involves the design of a multifunctional system based on gold nanoshells (AuNSs) decorated with lanthanide-based upconversion nanoparticles (UCNPs) intended as an optical heater and temperature probe at the nanoscale.

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Journal articles on the topic 'Optically induced heating'

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