Analytical solution for the dynamic behavior of erbium-doped fiber amplifiers with constant population inversion along the fiber

We present an analytical solution for the coupled rate and propagation equations for a dynamic two-level homogeneously broadened system interacting with radiation and with constant population inversion along the longitudinal axis of the fiber, z. We derive an analytical solution for the z dependence of these equations, which greatly simplifies the numerical solution for the output powers' time dependence. Amplified spontaneous emission and background loss influences are considered in the model, in contrast to the previous analytical solution presented by Y. Sun et al. The solution is derived, and the importance of each term for the dynamic modeling of typical erbium-doped fiber amplifiers is analyzed. (C) 2004 Optical Society of America.21101732173

SELF-DIFFRACTION IN POPULATION GRATINGS

481309131

HIGH-ORDER OPTICAL NONLINEARITIES IN SATURABLE ABSORBERS

111272

Amplification of broadband noise pumped by two lasers in optical fibers

A theoretical and experimental investigation of catastrophic amplification of broadband noise in optical fibers near the zero-dispersion frequency (v(0)) pumped by two lasers with frequencies that are symmetrically tuned relative to v(0) is presented. The effect is due to a four-wave mixing (FWM) process, phase matched up to third-order dispersion, between the spectral components of noise and the lasers. We observed a FWM gain of 16 dB (10-dB net gain) over a 22-nm bandwidth (limited by fourth-order dispersion) for 18-dBm power lasers at +/-1 THz (8 nm) from v(0) in a 25-km-long dispersion-shifted fiber. A simple analytical model is proposed that will permit us to investigate this effect numerically in amplified links with concatenated amplifiers and consider random fluctuations of v(0) along the fiber. (C) 2001 Optical Society of America.18101428143

SIDEBAND INTERACTIONS IN HOMOGENEOUSLY BROADENED SATURABLE ABSORBERS

2952716272

SPECTRAL NARROWING IN THE PROPAGATION OF CHIRPED PULSES IN SINGLE-MODE FIBERS

A theoretical study of the nonlinear propagation of picosecond chirped pulses in single-mode fibers is presented. We show that, under appropriate conditions, spectral narrowing-rather than broadening, as is generally believed-is induced, owing to the interplay of self-phase-modulation and dispersion. For downchirped pulses at a wavelength of 0.9 mum and a peak power as low as 0.1 W, substantial spectral narrowing occurs.18969970

Efficient calculation of higher-order optical waveguide dispersion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)An efficient numerical strategy to compute the higher-order dispersion parameters of optical waveguides is presented. For the first time to our knowledge, a systematic study of the errors involved in the higher-order dispersions' numerical calculation process is made, showing that the present strategy can accurately model those parameters. Such strategy combines a full-vectorial finite element modal solver and a proper finite difference differentiation algorithm. Its performance has been carefully assessed through the analysis of several key geometries. In addition, the optimization of those higher-order dispersion parameters can also be carried out by coupling to the present scheme a genetic algorithm, as shown here through the design of a photonic crystal fiber suitable for parametric amplification applications. (C) 2010 Optical Society of America181919522+Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [05/51689-2, 06/50912-2

Highly efficient generation of broadband cascaded four-wave mixing products

We report and investigate on a highly efficient technique to generate broadband cascaded four-wave mixing (FWM) products. It consists of launching two strong pump waves near the zero-dispersion wavelength of very short (of order of few meters) optical fibers. Simulations based on split step fourier method (SSFM) and experimental data demonstrate the efficiency of this approach. Multiple FWM products have been investigated by using conventional fibers and ultra-flattened dispersion photonic crystal fibers. Measured results present bandwidths of 300 nm with up to 118 FWM products. We have also demonstrated a flat bandwidth of 110 nm covering the C and L bands, with a small variation of only 1.2 dB between the powers of FWM products, achieved by using highly nonlinear fibers (HNLFs). The use of dispersion tailored photonic crystal fibers has been shown interesting for improving the multiple FWM efficiency and reducing the separation between the pump wavelengths. (c) 2008 Optical Society of America.1642816282

INCREASING THE EFFICIENCY OF CO2 TRANSVERSE ELECTRIC ATMOSPHERIC LASERS BY USE OF LOW IONIZATION-POTENTIAL ADDITIVES

52261261

Spectral evolution of a two-channel WDM system in the presence of modulation in instability

WDM optical communication systems operating in the anomalous dispersion region are shown to exhibit enhanced spectral broadening due to power phase-matched pumping of generated four-wave mixing spectral sidebands. In this regime, strong signal power modulation along the fiber takes place. We also show that nonzero dispersion-shifted fibers successfully overcome these problems. (C) 1999 John Wiley & Sons, Inc.20638939