Laterally complex-coupled DFB-lasers in the 1.55 /spl mu/m range based on GS-MBE-grown InGaAsP-InP

Distributed feedback (DFB) lasers have been fabricated using the concept of lateral complex coupling on InGaAsP/lnP laser structures grown by gas source molecular beam epitaxy. A periodic modulation of the complex refractive index is provided by a metal grating patterned laterally to the ridge. The evanescent field of the light wave couples to the grating, leading to single mode emission. Threshold currents of 20 mA and differential efficiencies of 0.15 W/A were obtained. Sidemode suppression ratios up to 50 dB and single mode output power levels over 15 mW have been achieved with these devices. A maximum small signal bandwidth of 16 GHz was measured.