Title :
Instability of coherence in semiconductor laser due to external feedback in hybrid-integrated optical waveguide components
Author :
Mitomi, Osamu ; Noguchi, Kazuto ; Yoshikini, Yuzo
Author_Institution :
NTT Opto-Electron. Lab., Kanagawa, Japan
fDate :
6/1/1990 12:00:00 AM
Abstract :
The coherence instability of oscillation-frequency shift and spectrum-linewidth fluctuation of a distributed feedback (DFB) semiconductor laser due to reflected feedback from input or output facets in a butt-coupled waveguide device is theoretically analyzed. A low-loss butt-coupling method between a semiconductor laser and a waveguide device for hybrid-integrated optical components used in coherent optical-fiber systems is presented. The calculated results indicate that (1) the coherence instability of the DFB lasers is sensitive to external optical feedback, (2) feedback from the waveguide input facet affects the laser frequency and gain shifts, and (3) feedback from the output facet intensifies the linewidth fluctuations
Keywords :
distributed feedback lasers; feedback; fibre optics; light coherence; optical communication equipment; optical couplers; semiconductor junction lasers; butt-coupled waveguide device; coherence instability; coherent optical-fiber systems; distributed feedback; external feedback; facets; gain shifts; hybrid-integrated optical waveguide components; laser frequency; linewidth fluctuations; low-loss butt-coupling method; optical coupling losses; oscillation-frequency shift; semiconductor laser; spectrum-linewidth fluctuation; waveguide input facet; Coherence; Distributed feedback devices; Laser feedback; Laser theory; Optical feedback; Optical waveguide theory; Optical waveguides; Output feedback; Semiconductor lasers; Waveguide lasers;
Journal_Title :
Lightwave Technology, Journal of
