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Bibliografie tematiche / Cross phase modulation

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Letteratura scientifica selezionata sul tema "Cross phase modulation"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 29 gennaio 2023

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Articoli di riviste sul tema "Cross phase modulation"

1

Samineni, Prathyush, Baolei Li, Jesse W. Wilson, Warren S. Warren e Martin C. Fischer. "Cross-phase modulation imaging". Optics Letters 37, n. 5 (21 febbraio 2012): 800. http://dx.doi.org/10.1364/ol.37.000800.

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2

Lesche, B., e W. Margulis. "Note on self-phase modulation and cross-phase modulation". Optics Communications 113, n. 4-6 (gennaio 1995): 481–86. http://dx.doi.org/10.1016/0030-4018(94)00532-y.

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3

Agrawal, Govind P. "Modulation instability induced by cross-phase modulation". Physical Review Letters 59, n. 8 (24 agosto 1987): 880–83. http://dx.doi.org/10.1103/physrevlett.59.880.

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4

Taoping Hu, Taoping Hu, e Xiaohan Sun Xiaohan Sun. "Modulation instability induced by cross-phase modulation with the fourth-order dispersion in dispersion-decreasing fiber". Chinese Optics Letters 11, n. 7 (2013): 070602–70606. http://dx.doi.org/10.3788/col201311.070602.

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5

Tsang, Mankei, e Demetri Psaltis. "Spectral phase conjugation with cross-phase modulation compensation". Optics Express 12, n. 10 (17 maggio 2004): 2207. http://dx.doi.org/10.1364/opex.12.002207.

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6

Islam, M. N., J. R. Simpson, H. T. Shang, L. F. Mollenauer e R. H. Stolen. "Cross-phase modulation in optical fibers". Optics Letters 12, n. 8 (1 agosto 1987): 625. http://dx.doi.org/10.1364/ol.12.000625.

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7

Blow, K. J., Rodney Loudon e Simon J. D. Phoenix. "Quantum theory of cross-phase modulation". Optics Communications 110, n. 1-2 (agosto 1994): 239–54. http://dx.doi.org/10.1016/0030-4018(94)90200-3.

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8

Ho, P. P., Q. Z. Wang, D. Ji, T. Jimbo e R. R. Alfano. "Harmonic cross phase modulation in ZnSe". Applied Physics Letters 54, n. 2 (9 gennaio 1989): 111–13. http://dx.doi.org/10.1063/1.101244.

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9

Hosseini, Mahdi, Stojan Rebić, Ben M. Sparkes, Jason Twamley, Ben C. Buchler e Ping K. Lam. "Memory-enhanced noiseless cross-phase modulation". Light: Science & Applications 1, n. 12 (dicembre 2012): e40-e40. http://dx.doi.org/10.1038/lsa.2012.40.

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10

Dinev, S. G., A. A. Dreischuh e S. Balushev. "Symbiotic light pairs sustained by self-phase modulation and cross-phase modulation". Physica Scripta 47, n. 6 (1 giugno 1993): 792–96. http://dx.doi.org/10.1088/0031-8949/47/6/017.

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Più fonti

Tesi sul tema "Cross phase modulation"

1

Sinclair, Gary F. "Cross-phase modulation in rubidium-87". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/735.

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2

Harrison, James Ashley. "All-optical processing using cross-phase modulation". Thesis, Aston University, 2005. http://publications.aston.ac.uk/8020/.

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The following thesis presents results obtained from both numerical simulation and laboratory experimentation (both of which were carried out by the author). When data is propagated along an optical transmission line some timing irregularities can occur such as timing jitter and phase wander. Traditionally these timing problems would have been corrected by converting the optical signal into the electrical domain and then compensating for the timing irregularity before converting the signal back into the optical domain. However, this thesis posses a potential solution to the problem by remaining completely in the optical domain, eliminating the need for electronics. This is desirable as not only does optical processing reduce the latency effect that their electronic counterpart have, it also holds the possibility of an increase in overall speed. A scheme was proposed which utilises the principle of wavelength conversion to dynamically convert timing irregularities (timing jitter and phase wander) into a change in wavelength (this occurs on a bit-by-bit level and so timing jitter and phase wander can be compensated for simultaneously). This was achieved by optically sampling a linearly chirped, locally generated clock source (the sampling function was achieved using a nonlinear optical loop mirror). The data, now with each bit or code word having a unique wavelength, is then propagated through a dispersion compensation module. The dispersion compensation effectively re-aligns the data in time and so thus, the timing irregularities are removed. The principle of operation was tested using computer simulation before being re-tested in a laboratory environment. A second stage was added to the device to create 3R regeneration. The second stage is used to simply convert the timing suppressed data back into a single wavelength. By controlling the relative timing displacement between stage one and stage two, the wavelength that is finally produced can be controlled.

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Docherty, Andrew Engineering UNSW. "Collision induced timing shifts in wavelength-division-multiplexed optical fiber communications systems". Awarded by:University of New South Wales. Engineering, 2004. http://handle.unsw.edu.au/1959.4/19337.

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Long distance repeaterless optical fiber communications systems are currently used to transmit most internet and telephone information worldwide. The growth of photonic telecommunications technology has produced systems with very high bit-rate per fiber, but this still falls short of its potential capacity. Currently systems that are able to transmit even higher bit-rates are being developed utilizing dense wavelength-division-multiplexing (WDM) to maximally utilize the bandwidth potential of optical fibers. One of the most important factors that limits the bit-rate achievable in a such a WDM optical communications system is the cross-talk between channels caused by pulse collisions. In this thesis a consistent mathematical theory is used to analyze the frequency and timing shifts caused collisions between two WDM channels. This theory is applied to the systems currently most promising for next-generation photonic telecommunications; the dispersion managed (DM) soliton and 'quasi-linear' systems. Self-contained formulae are obtained which accurately predict the timing shifts suffered in these systems with a wide range of parameters. These formulae require an order of magnitude less computational time that direct numerical simulations. Several mathematical techniques are introduced to obtain computationally efficient formulae for complete and incomplete collisions in both systems. For complete collisions we use the Poisson sum transform to change the calculation to a sum in the Fourier domain. For incomplete collisions we use asymptotic integration to obtain approximate formulae. For quasi-linear systems we simplify the Laplace method even further to obtain elementary formulae. We show that using a combination of these methods the timing shift for incomplete and complete collisions in a wide range of system configurations can be obtained in comparatively small computational times. We find that for systems with small DM map strength the timing shift from widely separated channels is significant. For quasi-linear systems with large DM map strength this is negligable and the timing shift decreases with the square of the channel frequency separation. We also find the timing shift from closely spaced channels is higher for quasi-linear systems than for DM soliton systems operating at the same average dispersion.

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4

Gamatham, Romeo Reginald Gunther. "Nonlinear effects with a focus on cross phase modulation and its impact on wavelength division multiplexing optical fibre networks". Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/6302.

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The demand for faster data transmission is ever increasing. Wavelength division multiplexing (WDM) presents as a viable solution to increase the data transmission rate significantly. WDM systems are based on the ability to transmit multiple wavelengths simultaneously down the fibre. Unlike time division multiplexing (TDM) systems, WDM systems do not increase the data transfer by increasing the transmission rate of a single channel. In WDM systems the data rate per channel remains the same, only multiple channels carry data across the link. Dense wavelength division multiplexing (DWDM) promises even more wavelengths packed together in the same fibre. This multiplication of channels increases the bandwidth capacity rapidly. Networks are looking into making use of technology that will ensure no electronic signal regeneration at any point within the DWDM network. Examples are; reconfigurable optical add/drop multiplexers (ROADM) and optical cross connect (OXC) units. These components essentially enable network operators to split, combine and multiplex optical signals carried by optical fibre. WDM allows network operators to increase the capacity of existing networks without expensive re-cabling. This provides networks with the flexibility to be upgraded to larger bandwidths and for reconfiguration of network services. Further, WDM technology opens up an opportunity of marketing flexibility to network operators, where operators not only have the option to rent out cables and fibres but wavelengths as well. Cross phase modulation (XPM) poses a problem to WDM networks. The refractive index experienced by a neighbouring optical signal, not only depends on the signal’s intensity but on the intensity of the co-propagating signal as well. This effect leads to a phase change and is known as XPM. This work investigates the characteristics of XPM. It is shown that, in a two channel WDM network, a probe signal’s SOP can be steered by controlling a high intensity pump signal’s SOP. This effect could be applied to make a wavelength converter. Experimental results show that the degree of polarization (DOP) of a probe signal degrades according to a mathematical model found in literature. The pump and probe signals are shown to experience maximum interaction, for orthogonal probe-pump SOP vector orientations. This may be problematic to polarization mode dispersion compensators. Additionally, experimental results point out that the SOP of a probe signal is much more active in the presence of a high intensity pump, as compared to the single signal transmission scenario.

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Ekvall, Karin. "Time resolved laser spectroscopy". Doctoral thesis, KTH, Physics, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3063.

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6

Rios, Clauson Sales do Nascimento. "ImplementaÃÃo de portas lÃgicas atravÃs da modulaÃÃo de pulsos por posiÃÃo (PPM) em filtros acÃstico-Ãpticos sintonizÃveis". Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2097.

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FundaÃÃo de Amparo Ã Pesquisa do Estado do CearÃ
Nesta dissertaÃÃo foi estudada a aplicaÃÃo do filtro AcÃstico-Ãptico SintonizÃvel (AOTF), com a ModulaÃÃo de Pulsos por PosiÃÃo (PPM), objetivando implementar, utilizando o mÃtodo de Runge-Kutta de 4a ordem, portas lÃgicas (OR-OU e AND-E) Ãpticas operando com pulsos de luz ultracurtos (2ps). Neste trabalho Ã investigado o desempenho das portas considerando vÃrios comprimentos do filtro ( L) que integra a sua estrutura interna, com o intuito de obter o comprimento de filtro mais adequado para uma operaÃÃo satisfatÃria, em regime dispersivo, nÃo linear, sem perdas e com modulaÃÃo de fase cruzada (XPM). Esta investigaÃÃo Ã realizada em duas situaÃÃes: primeiramente, sÃo considerados filtros com automodulaÃÃo de fase (SPM) e GVD (dispersÃo da velocidade de grupo). Em um segundo momento, as mesmas portas sÃo obtidas com efeitos SPM, XPM e GVD agindo juntos no AOTF. Foi observado que para pulsos do tipo sÃliton, os efeitos da dispersÃo, da nÃo linearidade e da modulaÃÃo de fase cruzada exercem juntos uma forte influÃncia na propagaÃÃo do mesmo, provocando a quebra do pulso na saÃda do dispositivo quando utilizamos um comprimento maior para os filtros. Para dispositivos mais curtos, o pulso chaveado apresentou compressÃes e alargamentos temporais e espectrais, bem comodeslocamentos temporais nos dois modo de propagaÃÃo (TE e TM). ApÃs a escolha de um comprimento de filtro adequado, foi selecionado um deslocamento temporal Ãtimo a ser aplicado nos pulsos de entrada para conseguirmos, na saÃda da porta lÃgica, deslocamentos temporais satisfatÃrios (acertos) na aplicaÃÃo da modulaÃÃo PPM. Em seguida, introduzimos fases em um dos pulsos de entrada (TM), provocando um defasamento entre os pulsos TE e TM, reduzindo ainda mais a margem de erro PPM de operaÃÃo das portas. Finalmente, ao analisarmos as fases aplicadas no pulso TM (0 a 2), definirmos o melhor Ãngulo de fase para que as portas operem na regiÃo de acerto da modulaÃÃo PPM.
In this dissertation it was studied the application of the Acoustic Optical Tunable Filter (AOTF), with Pulse Position Modulation (PPM), aiming at to implement, using the method of Runge-Kutta of 4a order, logical gates (OR and AND) optical operating with pulses of light ultra shorts (2ps). In this work the acting of the gates is investigated, considering several lengths of the filter (  L) that integrates your internal structure, with the intention of obtaining the length of more appropriate filter for a satisfactory operation, in dispersion regime, nonlinear, without losses and with Cross Phase Modulation (XPM). This investigation is accomplished in two situations: firstly, filters are considered with Self Phase Modulation (SPM) and GVD (group-velocity dispersion). In a second moment, the same gates are obtained with effects SPM, XPM and GVD, acting together in AOTF. It was observed that for pulses of the type soliton, the effects of the dispersion, of the nonlinearity and of the cross phase modulation exercise together a strong influences in the propagation of the same, provoking the break of the pulse in the exit of the device when we used a larger length for the filters. For shorter devices, the switched pulse presented temporary and spectral compression and spread, as well as, displacement in the time in the two propagation modes (TE and TM). After the choice of a length of appropriate filter, a great temporary displacement was selected to be applied in the input pulses for us to get, in the exit of the logical gate, satisfactory temporary displacements (successes) in the application of the PPM modulation. Soon after, we introduced phases in one of the entrance pulses (TM), provoking a phase displacement among TE and TM pulses, still reducing more the margin of error PPM of operation of the gates. Finally, to the we analyze the applied phases in the pulse TM (0 to 2), we defined the best phase angle for the gates to operate in the success area of the PPM modulation.

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7

Reis, Cláudia Sofia Marcos Machado. "All-optical routing functionalities". Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/12865.

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Doutoramento em Engenharia Eletrotécnica
All-optical solutions for switching and routing packet-based traffic are crucial for realizing a truly transparent network. To meet the increasing requirements for higher bandwidth, such optical packet switched networks may require the implementation of digital functions in the physical layer. This scenario stimulated us to research and develop innovative high-speed all-optical storage memories, focusing mainly on bistables whose state switching is triggered by a pulsed clock signal. In clocked devices, a synchronization signal is responsible for controlling the enabling of the bistable. This thesis also presents novel solutions to implement optical logic gates, which are basic building blocks of any processing system and a fundamental element for the development of complex processing functionalities. Most of the proposed schemes developed in this work are based on SOA-MZI structures due to their inherent characteristics such as, high extinction ratio, high operation speed, high integration capability and compactness. We addressed the experimental implementation of an all-optical packet routing scheme, with contention resolution capability, using interconnected SOAMZIs. The impact on the system performance of the reminiscent power of the blocked packets, from the non ideal switching performed by the SOA-MZIs, was also assessed.
As soluções totalmente óticas para a comutação e encaminhamento de pacotes de tráfego são cruciais para a realização de uma rede verdadeiramente transparente. Para atender às exigências crescentes de maior largura de banda, tais redes de comutação de pacotes óticos exigem a implementação de funções digitais na camada física. Este cenário estimulou-nos a investigar e a desenvolver memórias totalmente óticas, focando-nos principalmente na implementação de flip-flops óticos síncronos, cujo estado de comutação é accionado por um sinal de relógio. Esta tese também apresenta novas soluções para implementar portas lógicas óticas, visto estas serem um elemento fundamental para o desenvolvimento de funcionalidades complexas de processamento. A maioria dos esquemas propostos neste trabalho são baseados em estruturas interferométricas activas Mach-Zehnder (SOA-MZI) devido às suas características intrínsecas, nomeadamente, razão de extinção elevada bem como elevada capacidade de integração. A implementação experimental de um sistema de encaminhamento de pacotes totalmente ótico foi realizada usando cascatas de SOA-MZIs. O impacto da potência residual, devido à comutação não ideal dos SOA-MZIs, foi também analisado.

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8

Silva, Askery Alexandre Canabarro Barbosa da. "Da interação entre a modulação de fase cruzada e o tempo de atraso da resposta não-linear e seus efeitos na instabilidade modulacional de feixes co-propagantes". Universidade Federal de Alagoas, 2010. http://www.repositorio.ufal.br/handle/riufal/1689.

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Modulation instability (MI) is a general characteristic of wave propagation in nonlinear dispersive media and it has been intensively investigated in several branches of physics due to its fundamental nature as well as technological applications. This phenomenon corresponds to the exponential growth of weak harmonic perturbations in virtue of the interplay between dispersive and nonlinear effects. Hence, despite its important features, MI is also a main source of channel depletion and degradation in optical fiber communications. In this thesis, we investigate the modulational instability (MI) induced by cross-phase-modulation (XPM) of two incoherently coupled optical pulses co-propagating in a lossless fiber with a finite nonlinear response time. The non-instantaneous character of the nonlinear response is introduced through a Debye relaxation process. We analytically obtain the exact dispersion relation for weak harmonic perturbations over the stationary solution. We show that the instability spectrum, present in both normal and anomalous dispersive regimes in instantaneously responding Kerr media, develops a double peak structure whose relative strength and typical frequency range depend on the response time. Further, we reveal that there are two unstable modes in the entire frequency spectrum. We report the dependence of the maximum gain and central frequency within each unstable mode as a function of the group velocity mismatch and response time, showing the crossover between the regimes of fast and slow non-linear responses.
Fundação de Amparo a Pesquisa do Estado de Alagoas
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Instabilidade Modulacional (IM) é um fenômeno característico da propagação de ondas em meios dispersivos não-lineares e tem sido estudado em diversas áreas da Física devido a sua natureza fundamental bem como suas importantes plicações tecnológicas. Esse fenômeno corresponde ao enriquecimento exponencial de pequenas perturbações harmônicas devido a cooperação dos efeitos não-lineares e dispersivos. Portanto, não obstante sua aplicabilidade, IM é, de igual modo, uma fonte importante de degradação em sistemas de comunicação por fibras ópticas. Nesta tese investigamos a instabilidade modulacional (IM) induzida por Modulação de Fase Cruzada (MFC) de dois pulsos ópticos acoplados incoerentemente que se propagam em uma fibra sem perda com tempo de resposta não-linear finito. O caráter não-instantâneo da resposta não-linear é introduzido através de um processo de relaxação de Debye. Obtemos analiticamente, de modo exato, a relação de dispersão para fracas perturbações harmônicas da solução estacionária. Mostramos que o espectro de instabilidade, presente tanto no regime de dispersão normal quanto no anômalo em meios Kerr com resposta instantânea, desenvolve uma estrutura de pico duplo cuja a intensidade relativa e a frequência típica dependem do tempo de resposta considerado. Além do mais, revelamos que existem dois modos instáveis ao longo de todo o espectro de frequência. Apresentamos a dependência do ganho máximo e da frequência correspondente dentro de cada modo instável como função da diferença da velocidade de grupo e do tempo de resposta, mostrando o cruzamento entre os regimes de resposta não-linear rápida e lenta.

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Gemayel, Pierre. "Optique adaptative par modulateur spatial de lumière en microscopie et holographie". Thesis, Mulhouse, 2016. http://www.theses.fr/2016MULH9294/document.

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Depuis les années 50, la récupération de la phase d’un faisceau optique diffracté par un objet quelconque, est un sujet important dans plusieurs domaines scientifiques, comme la microscopie, l’astronomie et bien d’autres. Généralement, les méthodes qui le permettent se divisent en deux grandes catégories : les méthodes interférométriques et les méthodes itératives basées sur la propagation du faisceau. L’intérêt de ces dernières, réside dans le fait qu’elles sont moins sensibles au bruit, et leur implémentation expérimentale est plus simple. Aussi, le développement des techniques informatiques a rendu cette approche plus rapide et plus intéressante. Cependant, même si l’efficacité de ces méthodes a été démontrée dans plusieurs domaines, leur utilisation est restée limitée à cause de certaines exigences sur les conditions expérimentales, et à la non-convergence de leur algorithme vers une solution unique dans un grand nombre de cas. Ceci est encore plus vrai pour les objets dits "objets complexes", possédant une amplitude et une phase, ce qui réduit fortement leur champ d’application. Afin de surmonter ces problèmes de convergence, diverses stratégies expérimentales ont été développées. Elles ont toutes comme principe d’introduire de nouvelles contraintes bien connues dans le plan de l’objet. Cela permet d’augmenter le nombre de spectres acquis, et donc accroitre et diversifier les sources d’informations sur l’objet de base, ce qui va aider l’algorithme itératif à converger plus rapidement vers une solution finale et unique. Comme exemple de ces stratégies expérimentales, on peut acquérir plusieurs spectres provenant de différentes zones de l’objet, ou moduler la longueur d’onde du faisceau incident, ou même enregistrer les spectres dans des plans parallèles, connectés entre eux par la transformée de Fresnel. Dans ce contexte, le présent travail vise à démontrer expérimentalement une technique connue sous SSPR (Spread Spectrum Phase Retrieval), proposé en 2007 par Zhang, tout en lui introduisant un certain nombre de modifications, afin de la rendre plus pratique. L’idée consiste à moduler le front d’onde de l’objet par M phases aléatoires, générées avec un modulateur spatial de lumière à base de cristaux liquides (LC-SLM), puis enregistrer dans le plan de Fourier les M spectres correspondants. Ces M spectres seront ensuite utilisés dans un algorithme itératif permettant de remonter au front d’onde de l’objet initial, en simulant la propagation du front d’onde entre les deux espaces, spatial et fréquentiel.La première partie de cette thèse comporte une étude détaillée sur les modulateurs spatiaux de lumière, afin de pouvoir choisir le mieux adapté à notre application. Une fois que le modulateur à base de cristaux liquides (LC-SLM) est sélectionné, on présentera ses caractéristiques techniques, ainsi que les tests et les étapes de calibrations nécessaires pour assurer son fonctionnement linéaire et optimal. Ensuite, on montrera plusieurs types d’applications possibles avec ce composant, et dans divers domaines scientifiques, comme l’holographie, la microscopie, l’optique adaptative ainsi que les méthodes interférométriques permettant de reconstruire la phase d’un faisceau lumineux. Dans la deuxième grande partie, on concentre notre travail autour de la méthode itérative SSPR. On montrera comment on peut rendre l’application de cette méthode plus simple en utilisant un modulateur spatial de lumière à base de cristaux liquides, et en travaillant dans le plan de Fourier à la place du plan de Fresnel. Cependant, après avoir appliqué expérimentalement cette méthode, on remarque que les résultats obtenus sont très mauvais par rapport aux résultats des simulations. On effectue donc, une étude détaillée concernant les sources de bruits pouvant être responsable de la dégradation de la qualité des reconstructions obtenues. [...]
Since the 50s, recovering the phase information of a diffracted beam has a major interest in several fields such as microscopy, astronomy and many others. Generally, the solutions fall into two broad categories: interferometric methods and iterative methods based on beam propagation. The advantage of the latter is that they are less sensitive to noise, and their experimental implementation is simpler. Also, the progress in computer technologies as well in digital imaging devices makes the application of this approach easier and more interesting. However, even if the effectiveness of these methods has been demonstrated in several fields, their use remained limited because of certain requirements on the experimental conditions and the non-convergence of their algorithm to a single solution in many cases. This is even more true for the so-called "complex objects", having an amplitude and a phase, which can greatly reduce their field of application. To overcome the convergence problems and improve the robustness of these methods, many experimental strategies have been employed. They are all based on the same principle, which consists of introducing new well-known constraints in the object plane. This increases the number of acquired spectrum, and therefore diversifies the sources of information about the starting object, which will help the iterative algorithm to converge more quickly towards the final solution. As examples of such experimental strategies, one can record several spectra from different areas of the object, or modulate the wavelength of the incident beam, or also acquire the spectrums across two or more parallel planes connected through Fresnel or Fourier transform.In this context, the present work aims to experimentally demonstrate a technique known as SSPR (Spread Spectrum Phase Retrieval), proposed in 2007 by Zhang, while modifying it in order to make it more flexible. The idea is to introduce, using a liquid crystal spatial light modulator M strong phase modulation into the object field, then record in the Fourier plane the M corresponding spectrums. These M acquisitions will then be used in an iterative algorithm what will allow us to recover the object wavefront by simulating the propagation of the light between spatial and frequency spaces. The first part of this thesis includes a complete study on spatial light modulators; in order to select which one will be best suited for our application. Once liquid crystal spatial light modulators are selected, we present their technical characteristics, as well as the calibration tests needed to ensure their linear and optimal functioning. Then we show several possible applications with this type of component, in various scientific fields, like holography, microscopy, adaptive optics and interferometric methods to reconstruct the phase of a beam.In the second part, we focus our work around the SSPR iterative method. We will show how to make the application of this method simpler by using a liquid crystal spatial light modulator, and by working in Fourier plane instead of Fresnel plane. However, after applying SSPR we have noticed that the quality of experimental results is very inferior to the quality of simulation results. Therefore, a detailed study of the noise sources is conducted. Each of these noise sources adds its own contribution, yet modulator cross-talk remains the factor that deteriorates the most the quality of reconstruction. In fact liquid crystal spatial light modulators are known to have a strong cross-talk between their pixels commonly recognized as fringing field effect. As the pixels are micrometric, each addressed one affects its neighbors, and thus, the phase retardation obtained from a pixel will not be uniform over its entire surface. This will result in a blurring effect of the desired sharp edge between the pixels; therefore, the real displayed phase map will be very different from the addressed one. [...]

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10

Bock, Martin. "Programmable ultrashort highly localized wave packets". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16842.

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Die vorliegende Arbeit beschäftigt sich mit dem Konzept der radial nicht-oszillierenden, zeitlich stabilen ultrakurzen Bessel ähnlichen Strahlen oder "Nadelstrahlen" ("needle beams"), die zu einer Klasse von optischen hochlokalisierten Wellenpaketen generalisiert werden. Hierbei wird die Theorie über das räumlich-zeitlichen Ausbreitungsverhaltens von nicht auseinanderdriftenden Nadelstrahlen mit Pulsdauern von kleiner als 10 fs näher diskutiert. Dies wird durch eine systematische Darstellung der Methoden zur Generierung und Detektierung von lokalisierten Wellen komplettiert, die ein optischen Drehmoment tragen. Für die Erzeugung von HLWs kommen räumliche Lichtmodulatoren zum Einsatz, die ein flexibles Zuschneiden von Wellenpaketen mit der Dauer weniger Zyklen des EM-Feldes erlauben. Es wird gezeigt, dass solche optischen Pulse sich über beträchtliche Entfernungen ausbreiten, ohne dass sich dabei signifikant der Strahldurchmesser vergrößert oder der Puls zeitlich verbreitert. In variabler Weise werden verschiedene geometrische (z.B. ringförmige) Lichtverteilungen erzeugt. Anwendungspotential findet sich insbesondere in den Techniken der räumlichen Pulsformung und Diagnostik. Als besonders wichtiger Ansatz ist der Zeit-Wellenfront-Sensor zu erwähnen, welcher die nichtlineare, mehrkanalige Autokorrelation, die Wellenfrontdetektion mittels nichtdiffraktiver Teilstrahlen nach dem Shack-Hartmann-Prinzip und eine adaptive Funktionalität miteinander vorteilhaft verbindet. Das enorme Potential solcher Ansätze wird durch die hohe Genauigkeit orts-, winkel- und zeitabhängiger Rekonstruktionen der Wellenpakete nachgewiesen. Darüber hinaus ermöglicht das räumliche Kodieren und anschließende Verfolgen der Teilstrahlen eine wesentliche Verbesserung der Identifikation relevanter Parameter von Verteilungsfunktionen. Schließlich werden erste Schritte zur experimentellen Generation von optischen "light bullets" mit ganzzahligen und fraktalen orbitalen Drehmomenten präsentiert.
This thesis deals with the concept of radially non-oscillating, temporally stable ultrashort-pulsed Bessel-like beams or "needle pulses", which are an example of a highly localized wave packet (HLW). HLWs are the closest approximation of linear-optical light bullets and provide specific benefits compared to conventional Gaussian-like light bullets. The spatio-temporally nonspreading propagation behavior of few-cycle needle beams of less than 10 fs duration will be theoretically discussed in detail. An overview of the generation and detection of localized waves carrying an orbital angular momentum is also given. High fidelity spatial light modulators are used for the generation of HLWs. The flexible tailoring of few-cycle wave packets at near-infrared wavelengths is reported. It is shown that such pulses propagate over a huge depth of focus, neither significantly changing their spot size or nor the pulse duration. Variable geometrical distributions like circular disks, rings, or bars of light are shaped and exploited as building blocks for structures of higher complexity. Another section of the thesis emphasizes the numerous potential applications of related techniques for an optimized two-dimensional spatial pulse shaping and diagnostics (reduce ambiguities) based on localized waves. As a particularly important example, time-wavefront sensing is used to combine nonlinear multichannel autocorrelation with Shack-Hartmann wavefront sensing by means of localized sub-beams and adaptive functionality. The capabilities of such devices are illustrated by the results of angular and temporal mapping of few-cycle wave packets. Moreover, spatial encoding and subsequent tracking of individual sub-beams, even at incident angles of up to 50°, enables to significantly improve the spot recognition. Finally, first steps towards the generation of optical light bullets carrying integer or non-integer orbital angular momenta are presented.

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Capitoli di libri sul tema "Cross phase modulation"

1

Schneider, Thomas. "Self- and Cross-Phase Modulation". In Nonlinear Optics in Telecommunications, 143–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-08996-5_6.

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Ahmed, Jameel, Mohammed Yakoob Siyal, Freeha Adeel e Ashiq Hussain. "High-Nonlinearity in Glass Fibers and Cross-Phase Modulation". In Optical Signal Processing by Silicon Photonics, 53–68. Singapore: Springer Singapore, 2013. http://dx.doi.org/10.1007/978-981-4560-11-5_5.

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S., Sugumaran, Vamsi Nath Reddy P., Sirivella V. S. M. Reddy e Arulmozhivarman P. "Design of WDM Optical Networks for the Analysis of Cross Phase Modulation and Self Phase Modulation". In Communications in Computer and Information Science, 370–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29219-4_43.

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4

Ho, Keang-Po. "Cross-Phase Modulation-Induced Nonlinear Phase Noise for Quadriphase-Shift-Keying Signals". In Impact of Nonlinearities on Fiber Optic Communications, 325–41. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-8139-4_8.

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5

Thiele, Hans-Jörg, Robert I. Killey, Vitaly Mikhailov e Polina Bayvel. "Cross-Phase Modulation Distortion in Multi-Span Dense WDM Systems". In Optical Networking, 352–63. London: Springer London, 1999. http://dx.doi.org/10.1007/978-1-4471-0525-1_37.

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6

Göger, Gernot, e Bernhard Spinnler. "Analytical Model for Cross-Phase Modulation in Multi-span WDM Systems with Arbitrary Modulation Formats". In Networking - ICN 2005, 52–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/978-3-540-31956-6_7.

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7

Venkata Dharani, Ch, e A. Brintha Terese. "Mitigation of Cross-Phase Modulation in Multiband Radio Over Fiber Systems". In Lecture Notes in Electrical Engineering, 289–301. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-7293-2_31.

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8

Ripoche, J. F., M. A. Franco, G. Grillon, E. T. J. Nibbering, B. S. Prade e A. Mysyrowicz. "Dynamical Studies of Non-linear Refractive Index by Cross Phase Modulation". In Springer Series in Chemical Physics, 179–80. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-80314-7_77.

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9

Baldeck, P. L., R. R. Alfano e G. P. Agrawal. "Generation of Sub-100-fs Pulses at 532 nm from Modulation Instability Induced by Cross-Phase Modulation in Optical Fibers". In Ultrafast Phenomena VI, 53–55. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-83644-2_16.

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10

Baldeck, P. L., P. P. Ho e R. R. Alfano. "Cross-Phase Modulation: A New Technique for Controlling the Spectral, Temporal, and Spatial Properties of Ultrashort Pulses". In The Supercontinuum Laser Source, 117–83. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4757-2070-9_4.

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Atti di convegni sul tema "Cross phase modulation"

1

Samineni, Prathyush, Martin C. Fischer e Warren S. Warren. "Cross-phase Modulation Microscopy". In Laser Science. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/ls.2011.ltua2.

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2

Tsang, Mankei, e Demetri Psaltis. "Spectral phase conjugation with cross-phase modulation compensation". In Frontiers in Optics. Washington, D.C.: OSA, 2004. http://dx.doi.org/10.1364/fio.2004.fwh44.

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3

Slowik, Karolina, Andrzej Raczynski, Jaroslaw Zaremba, Sylwia Zielinska-Kaniasty, Maurizio Artoni e Giuseppe C. La Rocca. "Cross phase modulation in photonic crystals". In SPIE Optics + Optoelectronics, a cura di Mario Bertolotti. SPIE, 2011. http://dx.doi.org/10.1117/12.886760.

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4

Aakjer, Thomas, e Joern H. Povlsen. "Cross-phase modulation in fiber lasers". In SPIE's 1994 International Symposium on Optics, Imaging, and Instrumentation, a cura di Michel J. F. Digonnet. SPIE, 1994. http://dx.doi.org/10.1117/12.188716.

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5

Velchev, I., R. Pattnaik e J. Toulouse. "Cross-phase-modulation induced Modulation Instability in Raman fiber amplifiers." In Nonlinear Guided Waves and Their Applications. Washington, D.C.: OSA, 2002. http://dx.doi.org/10.1364/nlgw.2002.nltud9.

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6

Huang, S. Y., C. H. Pai, C. H. Lee, J. Y. Lin, J. Wang e S. Y. Chen. "Experimental observation of relativistic cross phase modulation". In International Quantum Electronics Conference, 2005. IEEE, 2005. http://dx.doi.org/10.1109/iqec.2005.1560987.

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7

Duchesne, D., R. Morandotti, G. A. Siviloglou, R. El-Gnainy, G. I. Stegeman, D. N. Christodoulides, D. Modotto et al. "Cross-Phase modulation in AlGaAs photonic nanowires". In 2007 Quantum Electronics and Laser Science Conference. IEEE, 2007. http://dx.doi.org/10.1109/qels.2007.4431341.

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Duchesne, D., R. Morandotti, G. A. Siviloglou, R. El-Ganainy, G. I. Stegeman, D. N. Christodoulides, D. Modotto et al. "Cross-Phase Modulation in AlGaAs Photonic Nanowires". In CLEO 2007. IEEE, 2007. http://dx.doi.org/10.1109/cleo.2007.4453564.

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9

Zhao, Ying, Zhenning Tao, Shoichiro Oda, Yasuhiko Aoki e Takeshi Hoshida. "Pilot Based Cross Phase Modulation Power Estimation". In Optical Fiber Communication Conference. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/ofc.2017.w1g.2.

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Wu, Zhaoxi, Yuanqing Huang, Zihua Weng, Huangping Yan, Yiju Wang, Jin Wan e Ruifang Ye. "Cascaded wavelength conversion based on cross-gain modulation and cross-phase modulation in SOAs". In Asia-Pacific Optical Communications, a cura di Dominique Chiaroni, Wanyi Gu, Ken-ichi Kitayama e Chang-Soo Park. SPIE, 2007. http://dx.doi.org/10.1117/12.743518.

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Rapporti di organizzazioni sul tema "Cross phase modulation"

1

Ho, P. P., e R. R. Alfano. Ultrafast Optical A/D Converter Using Cross Phase Modulation. Fort Belvoir, VA: Defense Technical Information Center, marzo 1996. http://dx.doi.org/10.21236/ada309494.

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2

Chen, C. J., P. K. A. Wai e C. R. Menyuk. Final report on spectral broadening by cross-phase modulation in linearly birefringent optical fibers. Office of Scientific and Technical Information (OSTI), dicembre 1993. http://dx.doi.org/10.2172/10144448.

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Barg, Rivka, Erich Grotewold e Yechiam Salts. Regulation of Tomato Fruit Development by Interacting MYB Proteins. United States Department of Agriculture, gennaio 2012. http://dx.doi.org/10.32747/2012.7592647.bard.

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Abstract (sommario):

Background to the topic: Early tomato fruit development is executed via extensive cell divisions followed by cell expansion concomitantly with endoreduplication. The signals involved in activating the different modes of growth during fruit development are still inadequately understood. Addressing this developmental process, we identified SlFSM1 as a gene expressed specifically during the cell-division dependent stages of fruit development. SlFSM1 is the founder of a class of small plant specific proteins containing a divergent SANT/MYB domain (Barg et al 2005). Before initiating this project, we found that low ectopic over-expression (OEX) of SlFSM1 leads to a significant decrease in the final size of the cells in mature leaves and fruits, and the outer pericarp is substantially narrower, suggesting a role in determining cell size and shape. We also found the interacting partners of the Arabidopsis homologs of FSM1 (two, belonging to the same family), and cloned their tomato single homolog, which we named SlFSB1 (Fruit SANT/MYB–Binding1). SlFSB1 is a novel plant specific single MYB-like protein, which function was unknown. The present project aimed at elucidating the function and mode of action of these two single MYB proteins in regulating tomato fruit development. The specific objectives were: 1. Functional analysis of SlFSM1 and its interacting protein SlFSB1 in relation to fruit development. 2. Identification of the SlFSM1 and/or SlFSB1 cellular targets. The plan of work included: 1) Detailed phenotypic, histological and cellular analyses of plants ectopically expressing FSM1, and plants either ectopically over-expressing or silenced for FSB1. 2) Extensive SELEX analysis, which did not reveal any specific DNA target of SlFSM1 binding, hence the originally offered ChIP analysis was omitted. 3) Genome-wide transcriptional impact of gain- and loss- of SlFSM1 and SlFSB1 function by Affymetrix microarray analyses. This part is still in progress and therefore results are not reported, 4) Search for additional candidate partners of SlFSB1 revealed SlMYBI to be an alternative partner of FSB1, and 5) Study of the physical basis of the interaction between SlFSM1 and SlFSB1 and between FSB1 and MYBI. Major conclusions, solutions, achievements: We established that FSM1 negatively affects cell expansion, particularly of those cells with the highest potential to expand, such as the ones residing inner to the vascular bundles in the fruit pericarp. On the other hand, FSB1 which is expressed throughout fruit development acts as a positive regulator of cell expansion. It was also established that besides interacting with FSM1, FSB1 interacts also with the transcription factor MYBI, and that the formation of the FSB1-MYBI complex is competed by FSM1, which recognizes in FSB1 the same region as MYBI does. Based on these findings a model was developed explaining the role of this novel network of the three different MYB containing proteins FSM1/FSB1/MYBI in the control of tomato cell expansion, particularly during fruit development. In short, during early stages of fruit development (Phase II), the formation of the FSM1-FSB1 complex serves to restrict the expansion of the cells with the greatest expansion potential, those non-dividing cells residing in the inner mesocarp layers of the pericarp. Alternatively, during growth phase III, after transcription of FSM1 sharply declines, FSB1, possibly through complexing with the transcription factor MYBI serves as a positive regulator of the differential cell expansion which drives fruit enlargement during this phase. Additionally, a novel mechanism was revealed by which competing MYB-MYB interactions could participate in the control of gene expression. Implications, both scientific and agricultural: The demonstrated role of the FSM1/FSB1/MYBI complex in controlling differential cell growth in the developing tomato fruit highlights potential exploitations of these genes for improving fruit quality characteristics. Modulation of expression of these genes or their paralogs in other organs could serve to modify leaf and canopy architecture in various crops.

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