In this paper, the coupled mode theory (CMT) is used to derive the corresponding stochastic differential equations (SDEs) for the modal amplitude evolution inside optical waveguides with random refractive index variations. Based on the SDEs, the ordinary differential equations (ODEs) are derived to analyze the statistics of the modal amplitudes, such as the optical power and power variations as well as the power correlation coefficients between the different modal powers. These ODEs can be solved analytically and therefore, it greatly simplifies the analysis.
View Article and Find Full Text PDFTelecommunication carriers have to estimate the Raman parameters of the fibers installed on their optical transport networks in order to facilitate the design of the next generation of high bit-rate Raman amplified-based transmission systems. This paper reports a very complete characterization of the most popular modern transmission fibers in terms of Raman efficiency, noise figure and double Rayleigh backscattering crosstalk. Our experiment is based on an averaged power analysis, applied to a counter-pumped long-haul distributed fiber Raman amplifier.
View Article and Find Full Text PDFWe demonstrate that direct sequence optical code- division multiple-access (DS-OCDMA) encoders and decoders using sampled fiber Bragg gratings (S-FBGs) behave as multipath interferometers. In that case, chip pulses of the prime sequence codes generated by spreading in time-coherent data pulses can result from multiple reflections in the interferometers that can superimpose within a chip time duration. We show that the autocorrelation function has to be considered as the sum of complex amplitudes of the combined chip as the laser source coherence time is much greater than the integration time of the photodetector.
View Article and Find Full Text PDFA generalized solution of the linear propagation equation is proposed in terms of chirped Gauss-Hermite orthogonal functions. Some well-known special cases are pointed out, and the usefulness of this approach in analyzing arbitrarily shaped chirped pulses in rapidly converging series is discussed.
View Article and Find Full Text PDF