Title :
Properties of quarter-wave-shifted DFB lasers in the presence of a taper
Author_Institution :
British Telecom Research Laboratories, Ipswich, UK
Abstract :
The deleterious effect of a taper on the properties of quarterwave-shifted DFB lasers is analysed to assess the tolerance of these potentially useful single-frequency lasers to variations in epitaxial layer thickness, composition or in the DFB grating period. The maximum tolerable variation in any of these parameters is shown to be relatively insensitive to the grating coupling strength. The maximum tolerable thickness variation depends principally on the derivative of the laser waveguide effective index with respect to epilayer thickness and, for typical diode parameters, lies in the range 150¿1500 Å.
Keywords :
diffraction gratings; distributed feedback lasers; laser modes; laser theory; optical waveguides; semiconductor junction lasers; 150 to 1500 Ã\x85; DFB grating period; DFB lasers; diode parameters; distributed feedback type; epilayer thickness; epitaxial layer taper; grating coupling strength; layer composition; maximum tolerable variation; quarter-wave-shifted; semiconductor lasers; single mode type; single-frequency lasers; waveguide effective index;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19870374
