Distributed feedback laser with holographic-defined phase-shifted gratings

Distributed feedback (DFB) lasers are popular light source in high-speed optical access networks; however, the production yield is generally low due to threshold degeneracy from uniform gratings. In this work a holographic-defined two-layer moiré grating structure is utilized to provide a quarter-wavelength phase shift in DFB lasers. In experiments, 200-μm-long DFB lasers exhibit excellent single-wavelength operating behavior (SMSR > 42 dB) in terms of Bragg wavelength, high-speed modulation capability (f
_3dB
= 22 GHz), and high device yield of 86% from 320 laser dies.