Structure-dependence of the chirp-to-power ratio spectrum for GaAs external cavity lasers

The chirp-to-power ratio (CPR) spectrum has been modeled for GaAs quantum well external cavity lasers. The model includes effects of transverse carrier spatial hole burning, finite carrier transport and capture time from the separate confinement-heterostructure (SCH) region to the quantum well region, and intrinsic material gain compression. The model explains the measured difference of the phase of the CPR at low modulation frequencies between GaAs quantum well and channel-substrate planar (CSP) lasers both in extended cavities. Our results indicate that the carrier effect in the SCH region can make a major contribution to the CPR.<>