Injected-carrier induced refractive-index change in semiconductor lasers

Abstract

A red-shift in the diode modes with increasing optical feedback is observed in external-cavity AlxGa1−xAs injection lasers. This shift is due to a change in the refractive index in the active region resulting from a reduction in the population-inversion induced by the optical feedback. This leads to a new determination of the carrier dependence of the refractive index at the laser wavelength in the active region of semiconductor lasers independent of current-induced thermal effects.