Open AccessLaterally‐coupled distributed feedback laser with first‐order gratings by interference lithography
Author(s) -
Li Jingsi,
Cheng Julian
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2013.1520
Subject(s) - interference (communication) , lithography , interference lithography , materials science , optics , optoelectronics , laser , distributed feedback laser , computer science , physics , telecommunications , medicine , channel (broadcasting) , alternative medicine , pathology , fabrication
The first laterally‐coupled distributed feedback (DFB) laser with first‐order sidewall gratings fabricated by optical interference lithography is experimentally demonstrated. The gratings were first etched into a dielectric mask on the planar top surface of an InP/AlGaInAs laser epiwafer, and then transferred to both sidewalls of a 2 µm deep ridge‐waveguide structure using a novel self‐aligned process. DFB ridge‐waveguide lasers with a cavity length of 650 µm and width of 2.6 µm (with 300 nm gratings on both sidewalls) achieved single longitudinal mode continuous‐wave operation, with a sidemode suppression ratio of 37 dB. The threshold current density is 1.7 kA/cm 2 at room temperature, and the slope efficiency is 0.14 mW/mA per facet (uncoated).