LOW-BIAS-CURRENT DIRECT MODULATION UP TO 33-GHZ IN INGAAS GAAS/ALGAASPSEUDOMORPHIC MQWRIDGE-WAVE-GUIDE LASERS/

Modulation bandwidths of 24 GHz (I(bias) = 25 mA) and 33 GHz (I(bias) = 65 mA) are demonstrated for 3 x 100 mum2 In0.35 Ga0.65 As/GaAs multi ple quantum well ridge-waveguide lasers with undoped and p-doped activ e regions, respectively. These performance enhancements have been achi eved both by lowering the growth temperature of the high-Al-mole-fract ion cladding layers and by utilizing short-cavity devices, fabricated with dry-etched facets using chemically-assisted ion-beam etching. Bot h the undoped and p-doped lasers also demonstrate modulation current e fficiency factors exceeding 5 GHz/mA1/2, the best reported results for any semiconductor laser.