We investigated differential gain, refractive index and (alpha) -parameter in strongly index and gain guided broad- area semiconductor optical amplifiers. The measured linewidth enhancement factor is larger than the values reported for narrow-stripe lasers and is consistent with theoretical predictions.
High quality traveling-wave semiconductor optical amplifiers were designed and fabricated for all-optical switching applications. We obtained 21 dB small signal gain with 0.16 dB gain ripple. Measured residual reflectivity was 5 X 10<SUP>-5</SUP> and the 3-dB gain bandwidth as wide as 70 nm. Our results show careful wavelength selection is required in order to match the amplifiers gain peak wavelength to the desired operating wavelength of the optical switches.