Title :
Effects of the random fluctuation in grating period on the characteristics of quarter-wavelength-shifted DFB lasers
Author :
Han, Jae-Woong ; Cha, Jung-Ho ; Kim, Sang-Bae
Author_Institution :
Sch. of Electron. Eng., Ajou Univ., Suwon, South Korea
Abstract :
Degradation in wavelength accuracy and single-mode stability, incurred by random fluctuation of grating period, has been studied by an effective-index transfer matrix method in quarter wavelength shifted distributed-feedback lasers. The laser facets are assumed to be perfectly antireflection coated, and the period fluctuation is modeled as a Gaussian random variable. Laser wavelength variation originates from period-fluctuation induced wavelength change and threshold gain variation. Threshold gain difference decreases with increasing period fluctuation irrespective of grating coupling coefficient, while spatial-hole-burning effect is exacerbated or alleviated in low- and high-coupling coefficient devices, respectively.
Keywords :
diffraction gratings; distributed feedback lasers; fluctuations; laser theory; matrix algebra; semiconductor device models; semiconductor lasers; Gaussian random variable; effective-index transfer matrix method; grating coupling coefficient; grating period; high-coupling coefficient devices; increasing period fluctuation; laser facets; laser wavelength variation; low-coupling coefficient device; perfectly antireflection coated; period fluctuation; period-fluctuation induced wavelength change; quarter-wavelength-shifted DFB lasers; random fluctuation; single-mode stability; spatial-hole-burning effect; threshold gain difference; threshold gain variation; wavelength accuracy; Fluctuations; Gratings; Laser modes; Laser stability; Mirrors; Optical waveguides; Random number generation; Semiconductor lasers; Transmission line matrix methods; Waveguide lasers;
Journal_Title :
Photonics Technology Letters, IEEE
