Title :
FM characteristics and compact modules for coherent semiconductor lasers coupled to an external cavity
Author :
Shin, Chul-Ho ; Teshima, Mitsuhiro ; Ohtsu, Motoichi ; Imai, Tohru ; Yoshida, Junichi ; Nishide, Kenichi
Author_Institution :
Tokyo Inst. of Technol., Yokohama, Japan
fDate :
3/1/1990 12:00:00 AM
Abstract :
Measured FM responses of a semiconductor laser optically coupled off-axis to a confocal Fabry-Perot cavity are discussed. It was found that this cavity acted as a frequency discriminator and as a phase comparator for slow and fast frequency fluctuations, respectively. The crossover between them was determined by a half linewidth of the cavity. On the basis of these investigations, two kinds of coherent semiconductor laser modules were constructed. External Fabry-Perot cavities were made by using an optical fiber and a hemispherical microlens. The linewidths of these lasers were less than 25 kHz.<>
Keywords :
fibre optics; frequency modulation; laser accessories; laser cavity resonators; lenses; light coherence; optical modulation; semiconductor junction lasers; spectral line breadth; FM characteristics; coherent semiconductor laser modules; coherent semiconductor lasers; compact modules; confocal Fabry-Perot cavity; coupled external laser cavities; crossover; external cavity; fast frequency fluctuations; frequency discriminator; half linewidth; hemispherical microlens; off-axis coupling; optical fiber; optically coupled; phase comparator; semiconductor laser linewidths; slow frequency fluctuations; Fiber lasers; Frequency modulation; Laser feedback; Laser noise; Laser stability; Optical coupling; Optical feedback; Optical noise; Resonance; Semiconductor lasers;
Journal_Title :
Photonics Technology Letters, IEEE
