THERMAL FREQUENCY DRIFT SUPPRESSION IN TUNABLE DFB LASERS BY PLASMA-INDUCED FREQUENCY-SHIFT ENHANCEMENT

The authors propose enhanced-plasma-effect (EPE) lasers for coherent o ptical frequency division multiplexed networks. In the EPE lasers, the blue frequency shift due to the plasma effect is enhanced by incorpor ating a very thick p-side optical guide layer as a carrier reservoir f or multiple quantum-well distributed feedback laser and it surpasses t he red frequency shift due to the thermal effect. The results of demon strating a frequency step response maintained in the blue shift region and an enhanced blue shift frequency modulation response over the who le modulation frequency range from DC are presented for the first time .