To see the other types of publications on this topic, follow the link: Pulsed laser excitation.
Dissertations / Theses on the topic 'Pulsed laser excitation'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 23 dissertations / theses for your research on the topic 'Pulsed laser excitation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Little, Helen. "Optical micromanipulation using ultrashort pulsed laser sources." Thesis, St Andrews, 2007. http://hdl.handle.net/10023/338.
Full text
2
Mauguet, Maxime. "Etude de la génération d'événements singuliers par excitation laser impulsionnel dans des composants silicium utilisés en environnement radiatif." Thesis, Toulouse, INSA, 2019. http://www.theses.fr/2019ISAT0012/document.
Full textAbstract:
Les composants électroniques utilisés pour des applications spatiales sont soumis à des rayonnements susceptibles de les rendre inopérants. Pour se prémunir de tels effets, leur sensibilité est testée au sol dans des accélérateurs de particules, onéreux et complexes à mettre en œuvre. Ce travail de thèse porte sur l’utilisation d’impulsions laser pour reproduire sous certaines conditions les effets des ions lourds. Le déclenchement de phénomènes parfois destructifs sur plusieurs types de composants de niveaux d’intégration différents a été obtenu sur le banc laser développé pendant cette thèse. Cela ouvre la voix à l’utilisation du laser comme outil de diagnostic en tirant partie de ses avantages en termes d’accessibilité, de coûts et de compréhension fine des effetsElectronic components used for space applications may exhibit failures under radiation. To prevent uch effects, the radiation sensitivity is evaluated using particle accelerators. Since those facilities are nly few around the world and expensive, complementary tests are needed to analyse radiation ensitivity. This work contributes to the use of laser pulses to reproduce under given conditions the ffects of heavy ions. Using the laser set-up developed during this thesis, single events which may be estructive were triggered on several types of electronic components. This paves the way to the use of aser as a diagnostic tool, given its advantages in terms of accessibility, costs and detailed analysis
3
Xu, Bingwei. "Control of multiphoton molecular excitation with shaped femtosecond laser pulses." Diss., Connect to online resource - MSU authorized users, 2008.
Find full text
4
Papastathopoulos, Evangelos. "Adaptive control of electronic excitation utilizing ultrafast laser pulses." Doctoral thesis, [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975015184.
Full text
5
Modoran, Georgia C. "Intense field electron excitation in transparent materials." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1133273960.
Full text
6
Wang, Xiong, Russell S. Witte, and Hao Xin. "Thermoacoustic and photoacoustic characterizations of few-layer graphene by pulsed excitations." AMER INST PHYSICS, 2016. http://hdl.handle.net/10150/615111.
Full textAbstract:
We characterized the thermoacoustic and photoacoustic properties of large-area, few-layer graphene by pulsed microwave and optical excitations. Due to its high electric conductivity and low heat capacity per unit area, graphene lends itself to excellent microwave and optical energy absorption and acoustic signal emanation due to the thermoacoustic effect. When exposed to pulsed microwave or optical radiation, distinct thermoacoustic and photoacoustic signals generated by the few-layer graphene are obtained due to microwave and laser absorption of the graphene, respectively. Clear thermoacoustic and photoacoustic images of large-area graphene sample are achieved. A numerical model is developed and the simulated results are in good accordance with the measured ones. This characterization work may find applications in ultrasound generator and detectors for microwave and optical radiation. It may also become an alternative characterization approach for graphene and other types of two-dimensional materials. (C) 2016 AIP Publishing LLC.
7
Lin, Jiunn-Yuan. "Optimisation of multi-pulse pumping for collisional excitation X-ray lasers." Thesis, University of Essex, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265028.
Full text
8
Raymond, Xavier. "Développement d'une source pulsée d'électrons extraits d'un plasma produit par laser." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0142/document.
Full textAbstract:
Ce manuscrit de thèse décrit le développement d'un faisceau d'électrons intense et bref qui s'insère dans le cadre de la recherche sur les propriétés nucléaires de la matière au sein des plasmas chauds et denses. Afin d'obtenir un tel faisceau, une nouvelle source a été imaginée, dont le principe est basé sur l'extraction des électrons d'un plasma produit par une impulsion laser intense. La caractérisation du plasma produit par laser lors de son expansion fait l'objet d'une première partie expérimentale de ce manuscrit. Ensuite, une différence de potentiel électrique de l'ordre de quelques kV appliquée sur le plasma lors de son expansion montre que l'extraction des électrons est un processus dynamique. Ces observations expérimentales sont validées par des études numériques à l'aide du code de simulation Particle-In-Cell "XOOPIC". Enfin, les distributions en surface et en énergie des électrons extraits du plasma sont déterminées expérimentalement et numériquement tout au long de l'expansion du plasma, ce qui fait l'objet d'une ultime partie de ce manuscrit. Pour cela, un détecteur de type Faraday Cup est utilisé. Une analyse de l'intensité d'émission du courant d'électrons via un modèle numérique met en évidence la présence d'un pré-plasma fournissant un champ électrique extracteur supplémentaireThis Ph.D thesis describes the development of an intense and brief electron beam and forms part of the research on the nuclear properties of matter in hot and dense plasmas. In order to obtain such a beam, a new source has been created, the principle is based on the extraction of electrons from a plasma produced by an intense laser pulse. The characterization of the laser-produced plasma during its expansion is the subject of a first experimental part of this thesis. Then, an electrical potential of the order of a few kV applied to the plasma during its expansion shows that the extraction of the electrons is a dynamic process. These experimental observations are validated by numerical studies using Particle-In-Cell simulation code "XOOPIC". Finally, the surface and energy distributions of the electrons extracted from the plasma are determined experimentally and numerically throughout the plasma expansion, which is the final part of this thesis. For this, a Faraday Cup type detector is used. An analysis of the emission intensity of the electron current with a numerical model shows the presence of a pre-plasma providing an additional extracting electric field
9
Vanne, Yulian V. "Ionization of molecular hydrogen in ultrashort intense laser pulses." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2010. http://dx.doi.org/10.18452/16107.
Full textAbstract:
Ein neuer numerischer ab initio Ansatz wurde entwickelt und zur Lösung der zeitabhängigen Schrödingergleichung für zweiatomig Moleküle mit zwei Elektronen (z.B. molekularer Wasserstoff), welche einem intensiven kurzen Laserpuls ausgesetzt sind, angewandt. Die Methode basiert auf der Näherung fester Kernabstände und der nicht-relativistischen Dipolnäherung und beabsichtigt die genaue Beschreibung der beiden korrelierten Elektronen in voller Dimensionalität. Die Methode ist anwendbar für eine große Bandbreite von Laserpulsparamtern und ist in der Lage, Einfachionisationsprozesse sowohl mit wenigen als auch mit vielen Photonen zu beschreiben, sogar im nicht-störungstheoretischen Bereich. Ein entscheidender Vorteil der Methode ist ihre Fähigkeit, die Reaktion von Molekülen mit beliebiger Orientierung der molekularen Achse im Bezug auf das linear polarisierte Laserfeld in starken Feldern zu beschreiben. Dementsprechend berichtet diese Arbeit von der ersten erfolgreichen orientierungsabhängigen Analyse der Multiphotonenionisation von H2, welche mit Hilfe einer numerischen Behandlung in voller Dimensionalität durchgeführt wurde. Neben der Erforschung des Bereichs weniger Photonen wurde eine ausführliche numerische Untersuchung der Ionisation durch ultrakurze frequenzverdoppelte Titan:Saphir-Laserpulse (400 nm) präsentiert. Mit Hilfe einer Serie von Rechnungen für verschiedene Kernabstände wurden die totalen Ionisationsausbeuten für H2 und D2 in ihren Vibrationsgrundzuständen sowohl für parallele als auch für senkrechte Ausrichtung erhalten. Eine weitere Serie von Rechnungen für 800nm Laserpulse wurde benutzt, um ein weitverbreitetes einfaches Interferenzmodel zu falsifizieren. Neben der Diskussion der numerischen ab initio Methode werden in dieser Arbeit verschiedene Aspekte im Bezug auf die Anwendung der Starkfeldnäherung für die Erforschung der Reaktion eines atomaren oder molekularen Systems auf ein intensives Laserfeld betrachtet.A novel ab initio numerical approach is developed and applied that solves the time-dependent Schrödinger equation describing two-electron diatomic molecules (e.g. molecular hydrogen) exposed to an intense ultrashort laser pulse. The method is based on the fixed-nuclei and the non-relativistic dipole approximations and aims to accurately describe both correlated electrons in full dimensionality. The method is applicable for a wide range of the laser pulse parameters and is able to describe both few-photon and many-photon single ionization processes, also in a non-perturbative regime. A key advantage of the method is its ability to treat the strong-field response of the molecules with arbitrary orientation of the molecular axis with respect to the linear-polarized laser field. Thus, this work reports on the first successful orientation-dependent analysis of the multiphoton ionization of H2 performed by means of a full-dimensional numerical treatment. Besides the investigation of few-photon regime, an extensive numerical study of the ionization by ultrashort frequency-doubled Ti:sapphire laser pulses (400 nm) is presented. Performing a series of calculations for different internuclear separations, the total ionization yields of H2 and D2 in their ground vibrational states are obtained for both parallel and perpendicular orientations. A series of calculations for 800nm laser pulses are used to test a popular simple interference model. Besides the discussion of the ab initio numerical method, this work considers different aspects related to the application of the strong-field approximation (SFA) for investigation of a strong-field response of an atomic and molecular system. Thus, a deep analysis of the gauge problem of SFA is performed and the quasistatic limit of the velocity-gauge SFA ionization rates is derived. The applications of the length gauge SFA are examined and a recently proposed generalized Keldysh theory is criticized.
10
De, Clercq Ludwig Erasmus. "Numerical modelling of the excitation of polyatomic molecules by femtosecond laser beams." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6522.
Full textAbstract:
Thesis (MSc)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: The selective excitation of an arbitrary vibrational level of a polyatomic molecule, without passage through an intermediary electronic excited state is demonstrated. This was achieved by simulating the interaction of a shaped, femtosecond pulse with one vibrational mode of the molecule. The carrier frequency of the pulse is chosen near resonant to the ground-to- rst-excited vibrational transition of the mode, and the pulse shape is optimized via closed-loop feedback. The simulation concentrates on the rst few vibrationally excited states since the density of states is still low, thus ensuring that the inter-vibrational decoherence time is relatively long compared to the pulse length. While various molecules were investigated this study focuses onUF6 for which detailed spectroscopic data for the v3 vibrational mode is available in literature. A multilevel model was developed and can be adapted for any number of levels. The model reported here was limited to a vibrational quantum number of four. The spectroscopic data included anharmonic splitting as well as forbidden transitions. The effect of rotational levels was not included. A density matrix approach was followed because this will allow for the introduction of dephasing of the coherent excitation via thermalizing collisions with the reservoir, as well as inter-vibrational relaxation. The time evolution of the density matrix is given by the Von Neumann equations.
AFRIKAANSE OPSOMMING: Die selektiewe opwekking van 'n arbitrêre vibrasionele vlak van 'n poliatomies molekule sonder oorgang na 'n intermediëre elektroniese opgewekte toetstand word gedemonstreer. Dit was bereik deur die interaksie te simuleer van 'n gevormde, femtosekonde pulse met een vibrasionele mode van 'n molekule. Die draer frekwensie van die pulse is so gekies dat dit naby resonansie van die grond-tot-eerste-opgewekte vibrasionele oorgang van die mode is, die puls vorm word geoptimeer deur 'n geslote-lus terugvoer. Die simulasie konsentreer op die eerste paar vibrasionele opgewekte toestande, omdat die digtheid van toestande nog steeds laag is, dus verseker dit dat inter-vibrasionele de-koherensie tyd relatief lank is in vergelyking met die puls se lengte. Verskillende molekules was ondersoek vir die studie. Die fokus is op UF6 waarvoor gedetaileerde spektroskopiese data vir die v3 vibrasionele beskikbaar is in die literatuur. 'n Multivlak model was ontwikkel en kan aangepas word vir enige aantal van vlakke. Die model wat hier aangemeld is, is beperk tot die vibrasionele kwantum getal van vier. Die spektroskopiese data het anharmonies splitting so wel as nie toegelaatbare oorgange bevat. Die effek van rotasionele vlakke was nie in berekening geneem nie. 'n Digtheids matriks benadering was gevolg, omdat dit toelaat vir die dekoherensie. Die tyd evolusie van die digtheids matriks word gegee deur die Von Neumann vergelykings.
11
Meng, Limin. "Experimental study and numerical simulations of the spectral properties of XUV lasers pumped by collisional excitation." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00790077.
Full textAbstract:
Improving the knowledge of the spectral and temporal properties of plasma-based XUV lasers is an important issue for the ongoing development of these sources towards significantly higher peak power. The spectral properties of the XUV laser line actually control several physical quantities that are important for applications, such as the minimum duration that can be achieved (Fourier-transform limit). The shortest duration experimentally achieved to-date is ~1 picosecond. The demonstrated technique of seeding XUV laser plasmas with a coherent femtosecond pulse of high-order harmonic radiation opens new and promising prospects to reduce the duration to a few 100 fs, provided that the gain bandwidth can be kept large enough.XUV lasers pumped by collisional excitation of Ni-like and Ne-like ions have been developed worldwide in hot plasmas created either by fast electrical discharge, or by various types of high-power lasers. This leads to a variety of XUV laser sources with distinct output properties, but also markedly different plasma parameters (density, temperature) in the amplification zone. Hence different spectral properties are expected. The purpose of our work was then to investigate the spectral behaviour of the different types of existing collisional excitation XUV lasers, and to evaluate their potential to support amplification of pulses with duration below 1 ps in a seeded mode.The spectral characterization of plasma-based XUV lasers is challenging because the extremely narrow bandwidth (typically ∆λ/λ ~10-5) lies beyond the resolution limit of existing spectrometers in this spectral range. In our work the narrow linewidth was resolved using a wavefront-division interferometer specifically designed to measure temporal coherence, from which the spectral linewidth is inferred. We have characterized three types of collisional XUV lasers, developed in three different laboratories: transient pumping in Ni-like Mo, capillary discharge pumping in Ne-like Ar and quasi-steady state pumping in Ne-like Zn. Besides the accurate measurement of the temporal coherence of the laser in each case, we have studied the spectral behaviour when the laser is operated in the saturation regime and (in Ni-like Mo) when it is seeded with high-order harmonic radiation. We have also investigated the temporal behaviour of the Ni-like Mo transient XUV laser, using an ultrafast X-ray streak camera. Our linewidth measurements are compared with detailed numerical calculations including relevant broadening mechanisms as well as radiative transfer effects. The evolution of the spectral profile with amplification and saturation was studied for different plasma parameters, and corresponding Fourier-transform limit duration were evaluated.The shortest temporal coherence (ie the largest bandwidth) is measured for the quasi-steady state pumping XUV laser, which operates at the highest density and ionic temperature.
12
Zier, Tobias [Verfasser]. "Ab-initio analysis of the structural response of solids after femtosecond-laser-pulse excitation : From understanding towards control / Tobias Zier." Kassel : Universitätsbibliothek Kassel, 2019. http://d-nb.info/1193090164/34.
Full text
13
Grigoryan, Naira [Verfasser]. "Excitation of Phonons in Solids and Nanostructures by Intense Laser and XUV Pulses and by Low Energy Atomic Collision / Naira Grigoryan." Kassel : Universitätsbibliothek Kassel, 2016. http://d-nb.info/1091589356/34.
Full text
14
Jobunga, Eric Ouma. "Beyond-the-dipole effects in strong-field photoionization using short intense laser pulses." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17653.
Full textAbstract:
Die Entwicklung Freier-Elektronen-Laser und einer neuen Generation von Strahlungsquellen erlaubt die Realisierung hoher Intensitäten und kurzer Pulsdauern. Im Regime niedriger Laserintensitäten war bisher die Dipolnäherung recht erfolgreich bei der Beschreibung der durch die Licht-Materie-Wechselwirkung erzeugten Dynamik, wodurch viele experimentell beobachtete Resultate reproduziert werden konnten. Bei den durch die neuen Strahlungsqullen erzeugten bisher unerreichten Intensitäten und Rönten-Wellenlängen kann die Dipolnäherung allerdings zusammenbrechen. Höhere Multipol-Wechselwirkungen, die mit dem Strahlungsdruck assoziiert werden, sollten dann erwartungsgemäß wichtig zur genauen Beschreibung der Wechselwirkungsdynamiken werden. In dieser Arbeit wird eine Methode zur Lösung der nichtrelativistischen zeitabhängigen Schrödingergleichung zur Beschreibung von Systemen mit einem einzelnen aktiven Elektron, das mit einem Laserfeld wechselwirkt, über die Dipolnäherung hinausgehend erweitert. Dabei wird sowohl die Taylor- als auch die Rayleight-Multipolentwicklung des Retardierungsterms ebener Wellen verwendet. Es wird erwartet, dass die Berücksichtigung höherer Ordnungen der Multipolwechselwirkung zu einer erhöhten Genauigkeit und Richtigkeit der Resultate führen. Weiterhin wird gezeigt, dass die Rayleigh-Multipolentwicklung für gleiche Laserparameter genauer ist und schneller zur Konvergenz der numerischen Rechnung führt. Die nicht-Dipoleffekte spiegeln is sowohl in den differentiellen als auch den totalen Ionisierungswahrscheinlichkeiten in Form von erhöhten Ionisierungsausbeuten, verzerrten ATI Strukturen und einer Asymmetrie in der Photoelektronenwinkelverteilung in der Polarisations und Propagationsrichtung wider. Es wird beobachtet, dass die nicht-Dipoleffekte mit der Intensität, Wellenlänge und Pulsdauer zunehmen. Es werden Ergebnisse sowohl für das Wasserstoffatom als auch das Heliumatom gezeigt.The development of free-electron lasers and new generation light sources is enabling the realisation of high intensities and short pulse durations. In the weak-field intensity regime, the electric dipole approximation has been quite successful in describing the light-matter interaction dynamics reproducing many of the experimentally observed features. But at the unprecedented intensities and x-ray wavelengths produced by the new light sources, the electric dipole approximation is likely to break down. The role of higher multipole-order terms in the interaction Hamiltonian, associated with the radiation pressure, is then expected to become important in the accurate description of the interaction dynamics. This study extends the solution of the non-relativistic time dependent Schrödinger equation for a single active electron system interacting with short intense laser pulses beyond the standard dipole approximation. This is realized using both the Taylor and the Rayleigh plane-wave multipole expansion series of the spatial retardation term. The inclusion of higher multipole-order terms of the interaction is expected to increase the validity and accuracy of the calculated observables relative to the experimental measurements. In addition, it is shown that for equivalent laser parameters the Rayleigh multipole expansion series is more accurate and efficient in numerical convergence. The investigated non-dipole effects manifest in both differential and total ionization probabilities in form of the increased ion yields, the distorted above-threshold-ionization structure, and asymmetry of the photoelectron angular distribution in both polarization and propagation directions. The non-dipole effects are seen to increase with intensity, wavelength, and pulse duration. The results for hydrogen as well as helium atom are presented in this study.
15
Gupta, Priya. "Pulsed dye laser for excitation of strontium." Thesis, 2004. http://hdl.handle.net/1911/17681.
Full textAbstract:
This thesis describes the construction and characterization of a high energy, tunable, pulsed dye laser that is used to make ultracold strontium plasma. In order to make ultracold plasma, we cool and trap strontium atoms in a magneto-optical trap (MOT) and then photoionize them with the dye laser. The dye laser is pumped by high-energy 355nm pulses from a commercial Nd:YAG laser and it gives out 10ns pulses of 400--415nm light with up to 50mJ/pulse. We will discuss the lasers spectrum, wavelength calibration, output power and efficiency for photoionizing strontium.
16
李俊樑. "Electric Waveform Synthesis by Ultrashort Laser Pulse Excitation and Related Techniques." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/62444871432795684857.
Full textAbstract:
碩士國立清華大學
電機工程學系
86
The major concern of the thesis is to develop the technique to extend the bandwidth of the electric pulse excited by ultrashort lasor pulses. We attempt to achieve this goal by synthesixing bipolar waveform and therefore eliminate the DC component of the electric signal, which will be more efficient to radiate. Non-uniform illuminating excitation was first applied to generate ultrashort electric pulses We obtained pulses with FWHM of barely 190 fs for which bandwidth is broader than 1.1 THz. Secondly, using two pump beams to excite two contiguors photoconductive switches, which were opopositely biased, was employed to synthesis a bipolar ultrafast electric puls. We demonstrated successfully that bipolar pulse synthesis method could significantly improve the bandwidth and eliminate the DC component us well. The synthesis of the bipolar ultrafast electric pulse also suggests the possibility of synthesizing usltrafast waveforms.
17
Papastathopoulos, Evangelos [Verfasser]. "Adaptive control of electronic excitation utilizing ultrafast laser pulses / vorgelegt von Evangelos Papastathopoulos." 2005. http://d-nb.info/975015184/34.
Full text
18
Han, Zung-Jie, and 韓宗潔. "Fourier-Floquet analysis of highly nonlinear atomic excitation by intense femto-second laser pulses." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/38742680415030058086.
Full textAbstract:
碩士國立交通大學
物理研究所
102
The atomic and molecular processes induced by intense (~1014 W/cm2) femto-second (10-15 s) lasers have attracted significant attention, both theoretical and experimental. When an intense femto-second laser is irradiated to a molecule, fluorescence signals are emitted from neutral fragments of the molecule. This phenomenon, called the neutral fragmentation, is expected to open new possibilities in laser technologies such as remote sensing and remote lasing. The mechanism may be understood as: (1) highly nonlinear excitation of the molecule, (2) the dissociation of the excited state molecule into electronically excited neutral fragments, (3) fluorescence from the neutral fragments. In spite of its importance, the mechanism of the highly nonlinear excitation has not been well understood. In this thesis, we take hydrogen atom as an example to examine the mechanism of the highly nonlinear excitation using the Fourier-Floquet spectra. We succeeded in proposing the detailed mechanism, which we find different depending on the parity of the angular momentum of the final state. Furthermore we have shown that the Ramsey fringe, which is believed only applicable in the perturbatively weak field, works nicely in highly nonlinear processes.
19
Lalanne, Elaine Nicole. "Nonlinear optical properties of novel nanostructured ion implanted laser ablated silicon using femtosecond pulse excitation." Thesis, 2003. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2003-077.
Full text
20
Wang, Chao. "Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257.
Full textAbstract:
This project explores optimization of two-photon excited fluorescence (TPEF) enhancement between tunable narrowband and un-tuned broadband femtosecond (fs) laser pulse excitations for two-photon microscopy (TPM). The research is conducted preliminarily in time domain and comprehensively in frequency domain to understand the physics behind TPEF enhancement by un-tuned sub-10 fs nearly transform-limited pulse (TLP) versus tunable 140 fs pulse. The preliminary study on inverse proportionality of TPEF yield to fs-pulse duration delimits a general lower-bound to narrowband fs-pulse regime (pulse duration > 40 fs) with assumption of dye-molecule frequency invariant response. Deviations from this inverse proportionality in broadband fs-pulse regime (pulse duration < 40 fs) highlights dye-molecule frequency variant response, necessity of group delay dispersion (GDD) compensation, and broadband TLP for TPEF enhancement.
The follow-up comparative study is made on un-tuned sub-10 fs TLP versus tunable 140 fs pulse excitations using three dye-phantoms (Indo-1, FITC, and TRITC) representative of fluorescent probes with similar TPEF characteristics. The integrated experimental system, with custom-designed GDD compensation, dispersion-less laser-beam expanding and focusing, and compound-lens for efficient fluorescence collection with good spectral resolution, ensures accurate TPEF measurements. Differentiated TPEF enhancements of Indo-1 (1.6), FITC (6.7), and TRITC (5.2) proportionally agree with calculated ones due to the overlap of fs-pulse second harmonic (SH) power spectrum with dye-molecule two-photon excitation (TPE) spectrum. Physically speaking, with broadband sub-10 fs TLP readily involved in both degenerate (v1 = v2) and non-degenerate (v1 ≠ v2) two-photon absorption (TPA), this un-tuned ultrashort fs-pulse excitation simultaneously allows for more accessibility to TPA-associated final states and diversely promotes population of thus excited dye-molecules with the three dye-phantoms. Under environmental influences (mutual quenching through one-photon absorption(s) and solvent effect), multicolor TPEF enhancement observed from a mixture of the three dyes shows promise of sub-10 fs TLP as simultaneous excitation for multiple-dye labeled samples in contrast to compromised excitation with narrowband fs-pulse tuning. Both single- and multicolor TPEF enhancements clarify tradeoff between tunability of narrowband fs-pulse and un-tuned broadband fs-pulse excitations, being instructive to further considerations on optimization of TPEF enhancement by strategic utilization of broadband fs-pulse for better performance of TPM.
21
Yen-hung, Chen, and 陳彥宏. "Estimate the gaseous collision effect and the pulse duration of Laser by one-photon and two-photon resonance excitation in Sodium vapor." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/13600742667861900942.
Full text
22
Chen, Yan-Hong, and 陳彥宏. "Estimate the gaseous collision effect and the pulse duration of Laser by one-photon and two-photon resonance excitation in Sodium vapor." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/87894139676582251145.
Full text
23
後藤, 俊夫, 明広 河野, 茂. 岸本, and 美根男 平松. "新しい縦型放電励起方式を用いた高速紫外パルスレーザの研究." 1991. http://hdl.handle.net/2237/12959.
Full text