Title :
Measurement of linewidth enhancement factor of semiconductor lasers by modified direct frequency-modulation method
Author :
Kikuchi, Kazuro ; Iwasawa, Hiroshi
Author_Institution :
Dept. of Electron. Eng., Tokyo Univ.
fDate :
6/23/1988 12:00:00 AM
Abstract :
The frequency modulation characteristics of 1.3 μm DFB lasers below the relaxation resonance reveal two different types of response: the in-phase response between the frequency modulation (FM) and the amplitude modulation (AM), and the out-of-phase response between them. In both cases, the ratio of the FM index to the AM index is strongly dependent on the modulation frequency; however, when the modulation frequency is increased beyond the relaxation resonance, this value approaches the linewidth enhancement factor. On the basis of this result, the linewidth enhancement factors of 1.3 μm DFB lasers with different amounts of wave-length detuning are determined
Keywords :
distributed feedback lasers; frequency modulation; laser transitions; laser variables measurement; optical modulation; semiconductor junction lasers; spectral line breadth; 1.3 micron; AM index; DFB lasers; FM index; amplitude modulation; frequency-modulation; in-phase response; linewidth enhancement factor; modified direct FM method; modulation characteristics; out-of-phase response; relaxation resonance; semiconductor lasers; wave-length detuning;
Journal_Title :
Electronics Letters
