Acoustooptic modulation resonances of injection lasers

A new approach is presented that explains the modulation resonance behavior of AlGaAs injection lasers as a consequence of collisions between photons and phonons in the lasing medium. The theory is applied to relate the laser's refractive index step with the measured modulation resonance frequency. Symmetrically located resonance peaks observed on unmodulated laser spectra are also explained with the new theory, which is compared with the conventional rate equation approach. Experimental data for modulated and unmodulated laser spectra and numerical calculations are presented in support of this acoustooptic theory.