EXPERIMENTAL CONFIRMATION OF INTERNAL SCATTERING AS A DOMINANT MECHANISM DETERMINING THE LONGITUDINAL MODE SPECTRA OF 1.3-MU-M SEMICONDUCTOR DIODE-LASERS

A residue that is characteristic of internal scattering is extracted from the below-threshold spectra of 1.3-mu-m semiconductor diode lasers by fitting a smooth function to the measured gain profile. The residue is found to be correlated with the above-threshold spectral output and can be used to predict and explain the above-threshold spectral tuning characteristics of the device. This suggests that the amount of scattering in the active region is an important quantity is determining the spectral output of semiconductor diode lasers.