F. Favre

Four-wave mixing in traveling-wave semiconductor laser amplifiers

Nondegenerate four-wave mixing (NDFWM) effects on simultaneous amplification of copropagating and counterpropagating waves with a frequency spacing of a few gigahertz in a 1.5- mu m nonresonant near traveling-wave semiconductor laser amplifier are discussed. Experimental results are in qualitative agreement with a theoretical model assuming the NDFWM process is mainly due to carrier pulsation produced by the beating of copropagating waves in the amplifier. The amplification of a phase-modulated wave is considered. Time-reversal properties of four-wave mixing are demonstrated. >

Experimental evidence of pseudoperiodical soliton propagation in dispersion-managed links

A new technique for measuring chirp evolution of Gaussian-like pulses transmitted on single-mode fiber is presented. It is used in a recirculation loop experiment to characterize propagation in anomalous-dispersion regime over megametrical distances. In-quadrature periodical variations of the two characteristic parameters of pulses (i.e., spectral width and chirp) are measured versus distance for different values of prechirp and in-line power. This constitutes the first experimental evidence of pseudoperiodical soliton propagation in dispersion-managed links. It also demonstrates that the prechirp is a key element for the control of nonlinearity as predicted by the theory.

Influence of extrinsic FM noise on laser diode linewidth measured by self-heterodyning

Abstract The relationship between low frequency fm-noise and linewidth of the light of monomode GaAlAs diode lasers has been studied. The linewidth has been determined directly by self-heterodyne measurements and indirectly from the noise level measured with an optical frequency discriminator. Level and shape of the frequency noise spectrum have been manipulated through the injection current and the effect upon the linewidth has been studied theoretically and experimentally. Good agreement has been found between the results of the linewidth and frequency noise measurements.

FM noise and linewidth reduction in a 1.5 μm InGaAsP DFB laser coupled to an external fiber resonator

Abstract We report linewidth measurements on a 1.5 μm distributed-feedback semiconductor laser coupled to an external single-mode fiber resonator. The laser linewidth has been reduced from 100 MHz to 150 kHz by weak optical feedback from a 40 cm long fiber resonator having a finesse of 22. FM noise spectrum measurements demonstrate that high linewidth reduction with damped resonant noise peaks can be achieved by using high finesse external resonators.

Experimental evidence of pseudo-periodical soliton propagation in dispersion-managed link

We present the first experimental evidence of pseudo-periodical soliton propagation in dispersion-managed link. It is shown that the prechirp is a key element for the control of nonlinearity as predicted by the theory. The aim of this study is to compare measured and predicted pulse evolution along a dispersion-managed link in the anomalous-dispersion regime using a recirculation loop with 100 km dispersion-compensated span of standard fiber. Simultaneous measurements of spectral width and chirp are performed for different values of prechirp.