Title :
High relaxation oscillation frequency operation of a QW-LD at the second quantized level
Author :
Takeshita, Tatsuya ; Ikeda, Masahiro
Author_Institution :
NTT Radio Commun. Syst. Labs., Kanagawa, Japan
fDate :
1/1/1994 12:00:00 AM
Abstract :
We describe a new approach for improving the relaxation oscillation frequency characteristics of quantum-well lasers at the second quantized level. Applying an antireflection (AR) and high-reflection (HR) coating to the laser facets suppresses lasing at the first quantized transition and promotes it at the second quantized transition. The relaxation oscillation frequency for the laser emitting at the second quantized transition is twice as high as that for the laser at the first quantized transition. The increase in the relaxation oscillation frequency of the laser operated at the second quantized transition is mainly due to the increase in the differential gain. Furthermore, the differential quantum efficiency increases to 0.5 in the AR/HR-coated laser
Keywords :
antireflection coatings; laser transitions; optical films; semiconductor lasers; AR/HR-coated laser; InGaAs-GaAs; QW-LD; antireflection coating; differential gain; first quantized transition; high relaxation oscillation frequency operation; high-reflection coating; laser facets; quantum-well lasers; second quantized level; Charge carrier density; Coatings; Frequency; Gallium arsenide; High speed optical techniques; Indium gallium arsenide; Laser transitions; Optical fiber communication; Optical modulation; Quantum well lasers;
Journal_Title :
Quantum Electronics, IEEE Journal of
