The results show that the spectrum of femtosecond pulse laser can be broadened effectively by using the laser spectrum broadening elements, and at some extent the spectrum gain narrowing effect of laser pulse can be effectively suppressed in the femtosecond laser amplifier.

Based on this background, the main problems including the noise in the Brillouin amplifier, the threshold value of stimulated Brillouin scattering(SBS), performance parameter optimization, Brillouin gain spectrum and amplified signal spectrum are investigated theoretically and experimentally.

Influences of the wavelength distribution and shift of the gain spectrum on picosecond optical pulses in semiconductor light amplifiers;

Modulation instability gain spectrum of cross-phase modulation in decreasing dispersion fiber;

In combination with the simulated results of the reflective spectrum and the gain spectrum at different temperatures,the measurement results have .

Taking into account the loss and the second-to fourth-order dispersions,the condition and gain spectra of modulation instability induced by cross-phase modulation in different dispersion regions of optical fibers are analyzed when the perturbation frequencies of the two optical waves are equal and unequal,respectively.

In case of co-existence of cubic and quintic nonlinearity,the condition and power gain spectra of modulation instability induced by the cross-phase modulation for two optical waves in loss,single-mode optical fibers are studied.