VERY-LOW CHIRPING OF INGAAS-INGAALAS MQW DFB BRS LASERS UNDER 10 GBIT/S MODULATION

The ability of the InGaAs/InGaAlAs MQW system for ultralow chirp operation under 10 Gbits/s operation is experimentally demonstrated. The MQW active layer has been grown by a solid-source MBE method. Two MOCVD regrowths were used to perform the DFB BRS lasers fabrication. DFB BRS lasers with good static and spectral performance have been obtained. Under 10 Gbits/s modulation those lasers exhibited a chirp value as low as 0.11 nm at -20 dB which is attributed to an extremely small phase-amplitude coupling coefficient 1.8. an analysis of the AM and FM modulated laser field under digital pseudorandom signal confirms the observed spectra and shows a possibility of an optimum spectrum width for lasers with small chirping.