Asymmetric nonlinear transmission spectra of Fabry-Pe´rot laser amplifiers

We investigate the nonlinear asymmetric transmission spectra of a semiconductor quantum-well Fabry-Pe´rot amplifier and present a method of extracting material parameters. Under large optical injection power, the transmission spectra are suppressed and become asymmetric. By measuring spectra at multiple wavelengths, the effect of the linewidth enhancement factor on the asymmetry is demonstrated. Through analysis of these spectra, we show that the linewidth enhancement factor can be extracted without knowledge of the injected power. Additionally, the saturation power of the amplifier can be found through curve fitting. The results are compared with those obtained from amplified spontaneous emission spectroscopy, showing close agreement. We also demonstrate that the nonlinear transmission spectra can be accurately modeled using a self-consistent approach.