Open AccessA laterally-coupled distributed feedback laser with equivalent quarter-wave phase shift
Author(s) -
Jingsi Li,
Julian Cheng
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.026936
Subject(s) - optics , materials science , photolithography , laser , electron beam lithography , lasing threshold , optoelectronics , grating , lithography , interference lithography , distributed feedback laser , photonic integrated circuit , semiconductor laser theory , fabrication , photonics , wavelength , resist , physics , nanotechnology , medicine , alternative medicine , layer (electronics) , pathology
We report the first laterally-coupled distributed feedback (LC-DFB) laser with a quarter-wave equivalent phase shift (EPS) realized by interference lithography (IL) and conventional photolithography. A specially designed sampled grating is fabricated on both sidewalls of a ridge waveguide to provide a quarter-wave EPS at the center of the cavity. The resulting laser exhibits stable single-mode lasing operation over a wide range of injection currents, with a side mode suppression ratio (SMSR) of 41.1 dB. This provides a practical, low-cost method to fabricate quarter-wave phase shifted DFB lasers with high performance without any epitaxial regrowth or the use of electron-beam lithography, thereby simplifying the fabrication of DFB lasers with stable and precise wavelengths, as single devices or as arrays in photonic integrated circuits.