Fenómenos de dispersión cromática asociados a la propagación de la radiación en sistemas ópticos Gaussianos. Diseño de compensadores de óptica difractiva y en óptica ultrarrápida y nuevas aplicaciones en óptica temporal.

RESUMEN En esta Tesis Doctoral se ha empleado el método de las matrices ABCD para, por una parte, abordar el diseño de sistemas ópticos compensadores de la dispersión cromática asociada a la difracción y, por otra, proponer nuevas aplicaciones en el ámbito de la propagación de pulsos en sistemas Gaussianos temporales. En ambos casos se han explotado las ventajas que ofrece el análisis matricial, haciendo especial hincapié en la interpretación física de las matrices ABCD que describen a los sistemas. Así, basándonos en el concepto de número de Fresnel colimado hemos desarrollado un nuevo procedimiento para conseguir, mediante el diseño de sistemas ópticos, la compensación de la dispersión cromática asociada a la difracción. El tratamiento matricial nos ha permitido establecer una regla que unifica el diseño de sistemas compensadores de la dispersión cromática en las regiones de Fourier y de Fresnel. En esta dirección, se ha propuesto un dispositivo óptico acromático mediante el cual es posible acromatizar cualquier patrón de difracción con sólo variar la longitud focal de la lente difractiva situada en su plano de entrada. Por otra parte, se ha demostrado que la adición de una lente difractiva en el plano de entrada de un procesador de Fourier compensado cromáticamente lo convierte en un procesador de Fresnel que, además, preserva el grado de acromatismo. Esta propiedad se ha aprovechado para diseñar un procesador de Fresnel acromático mediante el cual es posible reconocer patrones en color en función de su forma y localización. Dentro del campo de la difracción de haces pulsados, se ha demostrado la capacidad de los sistemas ópticos compensados cromáticamente para corregir la dispersión cromática asociada a la difracción de pulsos ultracortos de radiación. En el ámbito de la Óptica Temporal, se ha demostrado que la propagación de pulsos, con o sin chirp, en sistemas Gaussianos temporales puede describirse en términos de la evolución que experimentan los pulsos sin chirp en sistemas dispersivos parabólicos. En particular, el perfil de intensidad obtenido en el plano de salida de un sistema Gaussiano temporal coincide con una versión escalada de aquél que se obtiene mediante la propagación del paquete de ondas en un medio dispersivo parabólico. Aprovechando esta propiedad, se ha efectuado un análisis del efecto Talbot temporal en sistemas Gaussianos temporales a partir de la condición que establece la generación de autoimágenes temporales en un sistema dispersivo parabólico. Esta teoría general nos ha permitido abordar, como un ejemplo particular, la generación de autoimágenes de trenes de pulsos afectados por un chirp global. Esta variante del efecto Talbot temporal se ha propuesto como una técnica nueva para controlar, con alto grado de sintonización, la frecuencia de repetición y la modulación de trenes de pulsos. Por otra parte, hemos centrado nuestra atención en el problema de la compresión de pulsos mediante la propagación en medios dispersivos. En esta dirección, se ha introducido el concepto de desplazamiento de foco temporal y se ha derivado una expresión analítica que permite determinar el plano transversal en el que el pulso alcanza una anchura temporal mínima. Análogamente al efecto de desplazamiento de foco espacial, la compresión máxima no se consigue, en general, en el foco temporal del pulso con chirp. Finalmente, se ha demostrado que tanto el desplazamiento de foco temporal como el valor de la an-chura mínima únicamente dependen del número de Fresnel temporal efectivo de la geometría de compresión y del factor de calidad del pulso. Como ejemplo particular, se ha analizado el desplazamiento de foco que sufre un pulso con envolvente temporal super-Gaussiana de orden arbitrario y un paquete de ondas con perfil del tipo secante hiperbólica. ____________________________________________________________________________________________________In this doctoral thesis, a novel method for designing dispersion-compensated, broadband optical transformers has been proposed. As an application of this method, we have designed a novel optical setup that permits to carry out broadband dispersion compensation for a continuous set of Fresnel diffraction patterns by simply changing the focal length of a diffractive lens located at the input plane of the system. We have also demonstrated that the addition of a diffractive lens against the input plane converts any broadband dispersion-compensated Fourier processor into a dispersion-compensated Fresnel setup, and vice versa. Finally, the ability of the dispersion-compensated optical setups to correct the spatial chromatic-distortion associated with diffraction of femtosecond pulses has been analyzed. In a different context, distortions of linearly chirped signals induced by a general parabolic dispersive system have been discussed in-depth. This situation has subsequently been extended to any combination of time lenses and parabolic dispersive systems. In this respect, we have demonstrated that the output intensity signal from chirped-input propagation in an arbitrary temporal Gaussian system can always be identified with a magnified copy of the output signal obtained when the unchirped input propagates a certain evolution distance inside a parabolic dispersive fiber. As an application, these ideas have been particularized to a chirped periodic input signal and, then, we have analyzed a variant of the so-called temporal self-imaging effect that allowed us the achievement, from a single pulse train, of periodic pulse sequences with continuously variable repetition rate. On the other hand, propagation of linearly chirped pulses through a parabolic dispersive medium has been considered. In particular, we have derived an analytical formula of assessing the location of the transverse plane where the pulse width is minimum. Maximum pulse compression is not achieved, in general, at the so-called temporal focus of the chirped pulse. We demonstrate that both the relative temporal focal shift and the minimum pulse width are solely determined by two factors, the temporal equivalent of the Fresnel number of the geometry and the pulse quality factor. Some examples have been discussed

Proposed flat-topped pulses bursts generation using all-pass multi-cavity structures

We propose a simple lossless method for the generation of flat-topped intensity pulses bursts from a single utrashort pulse. We have found optimum solutions corresponding to different numbers of cavities and burst pulses, showing that the proposed all-pass structures of optical cavities, properly designed, can generate close to flat-topped pulse busts

All-pass optical structures for repetition rate multiplication

We propose and analyze several simple all-pass spectrally-periodic optical structures, in terms of accuracy and robustness, for the implementation of repetition rate multipliers of periodic pulse train with uniform output train envelope, finding optimum solutions for multiplication factors of 3, 4, 6, and 12

Spectral self-imaging effect by time-domain multilevel phase modulation of a periodic pulse train

[EN] We propose and analyze a novel (to our knowledge) approach to implement the spectral self-imaging effect of optical frequency combs. The technique is based on time-domain multilevel phase-only modulation of a periodic optical pulse train. The method admits both infinite- and finite-duration periodic pulse sequences. We show that the fractional spectral self-imaging effect allows one to reduce by an integer factor the comb frequency spacing. Numerical simulation results support our theoretical analysis. © 2011 Optical Society of America.This work has been supported by the Generalitat Valenciana (Grant GV/2009/044), by the Vicerrectorado de Investigacion, Universidad Politecnica de Valencia (Grant PAID-06-08/3276) and by the Ministerio de Ciencia e Innovacion of Spain under Project "Plan Nacional de I+D+I TEC2007-68065-C03-02". J. Caraquitena and M. Beltran also acknowledge financial support from the Ministerio de Ciencia e Innovacion through the "Juan de la Cierva" research program and FPI Grant BES-2006-12066, respectively.Caraquitena Sales, J.; Beltrán, M.; Llorente, R.; Martí Sendra, J.; Muriel, MA. (2011). Spectral self-imaging effect by time-domain multilevel phase modulation of a periodic pulse train. Optics Letters. 36(6):858-860. https://doi.org/10.1364/OL.36.000858S858860366Jannson, T., & Jannson, J. (1981). Temporal self-imaging effect in single-mode fibers. Journal of the Optical Society of America, 71(11), 1373. doi:10.1364/josa.71.001373Azaña, J., & Muriel, M. A. (1999). Technique for multiplying the repetition rates of periodic trains of pulses by means of a temporal self-imaging effect in chirped fiber gratings. Optics Letters, 24(23), 1672. doi:10.1364/ol.24.001672Arahira, S., Kutsuzawa, S., Matsui, Y., Kunimatsu, D., & Ogawa, Y. (1998). Repetition-frequency multiplication of mode-locked pulses using fiber dispersion. Journal of Lightwave Technology, 16(3), 405-410. doi:10.1109/50.661368Longhi, S., Marano, M., Laporta, P., Svelto, O., Belmonte, M., Agogliati, B., … Ibsen, M. (2000). 40-GHz pulse-train generation at 15 µm with a chirped fiber grating as a frequency multiplier. Optics Letters, 25(19), 1481. doi:10.1364/ol.25.001481Azaña, J. (2005). Spectral Talbot phenomena of frequency combs induced by cross-phase modulation in optical fibers. Optics Letters, 30(3), 227. doi:10.1364/ol.30.000227Bellemare, A., Karasek, M., Rochette, M., LRochelle, S., & Tetu, M. (2000). Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid. Journal of Lightwave Technology, 18(6), 825-831. doi:10.1109/50.848393Caraquitena, J., & Martí, J. (2009). Dynamic spectral line-by-line pulse shaping by frequency comb shifting. Optics Letters, 34(13), 2084. doi:10.1364/ol.34.002084Azaña, J., & Gupta, S. (2006). Complete family of periodic Talbot filters for pulse repetition rate multiplication. Optics Express, 14(10), 4270. doi:10.1364/oe.14.004270Caraquitena, J., Jiang, Z., Leaird, D. E., & Weiner, A. M. (2007). Tunable pulse repetition-rate multiplication using phase-only line-by-line pulse shaping. Optics Letters, 32(6), 716. doi:10.1364/ol.32.000716Jiang, Z., Huang, C.-B., Leaird, D. E., & Weiner, A. M. (2007). Optical arbitrary waveform processing of more than 100 spectral comb lines. Nature Photonics, 1(8), 463-467. doi:10.1038/nphoton.2007.139Weiner, A. M. (2000). Femtosecond pulse shaping using spatial light modulators. Review of Scientific Instruments, 71(5), 1929-1960. doi:10.1063/1.1150614Kolner, B. H. (1994). Space-time duality and the theory of temporal imaging. IEEE Journal of Quantum Electronics, 30(8), 1951-1963. doi:10.1109/3.301659Godil, A. A., Auld, B. A., & Bloom, D. M. (1994). Picosecond time-lenses. IEEE Journal of Quantum Electronics, 30(3), 827-837. doi:10.1109/3.286176Salem, R., Foster, M. A., Turner, A. C., Geraghty, D. F., Lipson, M., & Gaeta, A. L. (2008). Optical time lens based on four-wave mixing on a silicon chip. Optics Letters, 33(10), 1047. doi:10.1364/ol.33.001047Winzer, P. J., & Essiambre, R.-J. (2006). Advanced Modulation Formats for High-Capacity Optical Transport Networks. Journal of Lightwave Technology, 24(12), 4711-4728. doi:10.1109/jlt.2006.88526

Optical frequency comb technology for ultra-broadband radio-frequency photonics

The outstanding phase-noise performance of optical frequency combs has led to a revolution in optical synthesis and metrology, covering a myriad of applications, from molecular spectroscopy to laser ranging and optical communications. However, the ideal characteristics of an optical frequency comb are application dependent. In this review, the different techniques for the generation and processing of high-repetition-rate (>10 GHz) optical frequency combs with technologies compatible with optical communication equipment are covered. Particular emphasis is put on the benefits and prospects of this technology in the general field of radio-frequency photonics, including applications in high-performance microwave photonic filtering, ultra-broadband coherent communications, and radio-frequency arbitrary waveform generation.Comment: to appear in Laser and Photonics Review

Reconfigurable multiwavelength source based on electrooptic phase modulation of a pulsed laser

[EN] A reconfigurable multiwavelength source based on time-domain electrooptic phase modulation of a pulsed laser is proposed and experimentally demonstrated. The technique permits great reconfiguration in the spectrum allocation and wavelength separation. A tunable 5-GHz and 2.5-GHz frequency spacing from a 10-GHz mode-locked laser is experimentally demonstrated. A 5-GHz frequency shift is also demonstrated.Manuscript received March 02, 2011; revised April 21, 2011; accepted May 21, 2011. Date of publication May 27, 2011; date of current version July 27, 2011. This work was supported in part by the European Commission under the FP7-ICT-249142 FIVER and FP7-ICT-216863 BONE Projects. The work of M. Beltran was supported by the Ministerio de Ciencia e Innovacion, Spain, under FPI Grant BES-2006-12066.Beltrán Ramírez, M.; Caraquitena Sales, J.; Llorente Sáez, R.; Martí Sendra, J. (2011). Reconfigurable multiwavelength source based on electrooptic phase modulation of a pulsed laser. IEEE Photonics Technology Letters. 23(16):1175-1177. https://doi.org/10.1109/LPT.2011.2157967S11751177231