An asymmetric cladding gain-coupled DFB laser with oxide defined metal surface grating by MOCVD

摘要

A single growth step ridge waveguide InGaAs-GaAs distributed-feedback (DFB) laser with first-order silicon dioxide defined titanium surface gratings is described. The Ti grating introduces a periodic variation of the loss in the cavity to promote single-frequency emission. The device operates on a single longitudinal and lateral mode, with a threshold current of 20.5 mA, slope efficiency of 0.1 W/A and a side-mode-suppression ratio (SMSR) of approximately 40 dB. Moreover, a narrow spectral linewidth of about 40 kHz is achieved at an output power of 3 mW.