Correlation of electron density changes with optical frequency shifts in optically injected semiconductor lasers

We have studied experimentally and theoretically the dynamics of electron density in a semiconductor laser subject to a wide range of optical injection strength. Within the locking bandwidth, three-dimensional injection locking stability maps were generated to present a complete picture of locking. Beyond the locking range, resonance frequency shifts were observed and systematically investigated. This phenomenon was successfully correlated with the variation of carrier density and theoretically verified.