Generalized Bloch wave analysis for fiber and waveguide gratings

We have developed a generalized Bloch wave approach for the analysis of aperiodic gratings. This method yields both a macroscopic (i.e., reflection or transmission coefficient) as well as a microscopic (i.e., dispersion diagram and microstructure of the propagating internal field) characterization of fiber and waveguide aperiodic gratings

Formula for two-carrier intermodulation distortion in wavelength converted subcarrier multiplexed signals via cross gain modulation

We present, for the first time to our knowledge, closed expression for the computation of the harmonic and intermodulation distortions that appear on a wavelength converted two-tone subcarrier modulation (SCM) signal via cross gain modulation

Quantum Modelling of Electro-Optic Modulators

Many components that are employed in quantum information and communication systems are well known photonic devices encountered in standard optical fiber communication systems, such as optical beamsplitters, waveguide couplers and junctions, electro-optic modulators and optical fiber links. The use of these photonic devices is becoming increasingly important especially in the context of their possible integration either in a specifically designed system or in an already deployed end-to-end fiber link. Whereas the behavior of these devices is well known under the classical regime, in some cases their operation under quantum conditions is less well understood. This paper reviews the salient features of the quantum scattering theory describing both the operation of the electro-optic phase and amplitude modulators in discrete and continuous-mode formalisms. This subject is timely and of importance in light of the increasing utilization of these devices in a variety of systems, including quantum key distribution and single-photon wavepacket measurement and conformation. In addition, the paper includes a tutorial development of the use of these models in selected but yet important applications, such as single and multi-tone modulation of photons, two-photon interference with phase-modulated light or the description of amplitude modulation as a quantum operation.Comment: 29 pages, 10 figures, Laser and Photonics Reviews (in press

Harmonic distortion in microwave photonic filters

This paper was published in OPTICS EXPRESS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.20.008871 . Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under lawWe present a theoretical and experimental analysis of nonlinear microwave photonic filters. Far from the conventional condition of low modulation index commonly used to neglect high-order terms, we have analyzed the harmonic distortion involved in microwave photonic structures with periodic and non-periodic frequency responses. We show that it is possible to design microwave photonic filters with reduced harmonic distortion and high linearity even under large signal operation. © 2012 Optical Society of America.The authors wish to acknowledge the financial support given by the Research Excellency Award Program GVA PROMETEO 2008/09 and the FEDER Program "Instrumentacion Avanzada para Comunicaciones Opticas" with reference UPVOV08-3E-008.Rius Mercado, M.; Mora Almerich, J.; Bolea Boluda, M.; Capmany Francoy, J. (2012). Harmonic distortion in microwave photonic filters. Optics Express. 20(8):8871-8876. doi:10.1364/OE.20.008871S88718876208Capmany, J., & Novak, D. (2007). Microwave photonics combines two worlds. Nature Photonics, 1(6), 319-330. doi:10.1038/nphoton.2007.89Yao, J. (2009). Microwave Photonics. Journal of Lightwave Technology, 27(3), 314-335. doi:10.1109/jlt.2008.2009551Capmany, J., Ortega, B., & Pastor, D. (2006). A tutorial on microwave photonic filters. Journal of Lightwave Technology, 24(1), 201-229. doi:10.1109/jlt.2005.860478Minasian, R. A., Alameh, K. E., & Chan, E. H. W. (2001). Photonics-based interference mitigation filters. IEEE Transactions on Microwave Theory and Techniques, 49(10), 1894-1899. doi:10.1109/22.954804Bolea, M., Mora, J., Ortega, B., & Capmany, J. (2010). Photonic arbitrary waveform generation applicable to multiband UWB communications. Optics Express, 18(25), 26259. doi:10.1364/oe.18.026259Capmany, J., Pastor, D., & Ortega, B. (1999). New and flexible fiber-optic delay-line filters using chirped Bragg gratings and laser arrays. IEEE Transactions on Microwave Theory and Techniques, 47(7), 1321-1326. doi:10.1109/22.775473Mora, J., Ortega, B., Capmany, J., Cruz, J., Andres, M., Pastor, D., & Sales, S. (2002). Automatic tunable and reconfigurable fiberoptic microwave filters based on a broadband optical source sliced by uniform fiber Bragg gratings. Optics Express, 10(22), 1291. doi:10.1364/oe.10.001291Capmany, J., Mora, J., Ortega, B., & Pastor, D. (2005). Microwave photonic filters using low-cost sources featuring tunability, reconfigurability and negative coefficients. Optics Express, 13(5), 1412. doi:10.1364/opex.13.001412Huang, T. X. H., Yi, X., & Minasian, R. A. (2011). Single passband microwave photonic filter using continuous-time impulse response. Optics Express, 19(7), 6231. doi:10.1364/oe.19.006231Dai, Y., & Yao, J. (2008). Nonuniformly-spaced photonic microwave delayline filter. Optics Express, 16(7), 4713. doi:10.1364/oe.16.004713Mora, J., Ortega, B., Diez, A., Cruz, J. L., Andres, M. V., Capmany, J., & Pastor, D. (2006). Photonic microwave tunable single-bandpass filter based on a Mach-Zehnder interferometer. Journal of Lightwave Technology, 24(7), 2500-2509. doi:10.1109/jlt.2006.874652Marcuse, D. (1980). Pulse distortion in single-mode fibers. Applied Optics, 19(10), 1653. doi:10.1364/ao.19.00165