Title :
Mode stabilization method for superstructure-grating DBR lasers
Author :
Ishii, Hiroyuki ; Kano, Fumiyoshi ; Yoshikuni, Yuzo ; Yasaka, Hiroshi
Author_Institution :
NTT Opto-Electron. Labs., Kanagawa, Japan
fDate :
3/1/1998 12:00:00 AM
Abstract :
A wavelength stabilization method for widely tunable superstructure-grating (SSG) distributed Bragg reflector (DBR) laser is described. The output characteristics under tuning are studied theoretically and experimentally. It is found that peak reflectivity states, in which the lasing mode is just aligned with the reflection peaks of both DBR´s, are obtained at saddle points in the output characteristics while changing the two SSG-DBR currents. Based on these results, a method for the Bragg frequency control of the two SSG-DBRs is proposed. The feedback control circuit keeps the lasing mode at a peak reflectivity state, and it suppresses mode hopping. Additionally, the oscillation mode is locked to arbitrary reference wavelengths of an optical filter. Stabilization at 200 GHz (1.6 nm)-spaced 16 wavelengths was achieved within the wide tuning range of the SSG-DBR laser. Control was maintained under a laser temperature variation of ±5°C as a result of the Bragg frequency control of the two DBR´s
Keywords :
diffraction gratings; laser modes; laser stability; laser tuning; optical transmitters; reflectivity; semiconductor lasers; Bragg frequency control; SSG-DBR currents; arbitrary reference wavelengths; feedback control circuit; lasing mode; mode hopping; mode stabilization method; oscillation mode; output characteristics; peak reflectivity state; peak reflectivity states; reflection peaks; saddle points; superstructure-grating DBR lasers; wavelength stabilization method; widely tunable superstructure-grating DBR laser; Distributed Bragg reflectors; Frequency control; Laser mode locking; Laser modes; Laser stability; Laser theory; Laser tuning; Optical reflection; Reflectivity; Tunable circuits and devices;
Journal_Title :
Lightwave Technology, Journal of
