Determination of the dependence of the refractive index of the active region of an injection laser on the carrier density

A method was developed for determination of the dependence of the refractive index n of the active region of an injection laser on the carrier density N. The ratio Δn/ΔN was determined for AlGaAs/GaAs injection lasers with different thicknesses of the active region. It was found experimentally that the value of Δn/ΔN for a mode emitted by a quantum-well laser with an active layer ~ 20 nm thick was an order of magnitude less than for conventional injection lasers.