Anomalous effect of carriers on dielectric constant of (In,Ga)(As,P) lasers operating at 1.3 ¿m wavelength

Injected carriers were found to reduce the dielectric constant of the active layer by the unexpectedly high value of 0.4. This is a factor of approximately four greater than measured for GaAs/(Ga, Al)As lasers and also higher than other reported values for (In,Ga)(As,P) lasers operating at a wavelength of 1.6 ¿m. The technique employed was the observation of the spectral shift of individual Fabry-Perot modes of oxide insulated stripe lasers down to very low currents below threshold.