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 quan tum well external cavity lasers. The model includes effects of transve rse carrier spatial hole burning, finite carrier transport and capture time from the separate-confinement-heterostructure (SCH) region to th e quantum well region, and intrinsic material gain compression. The mo del explains the measured difference of the phase of the CPR at low mo dulation frequencies between GaAs quantum well and channel-substrate p lanar (CSP) lasers both in extended cavities. Our results indicate tha t the carrier effect in the SCH region can make a major contribution t o the CPR.