Title :
Very-low-threshold, highly efficient, and low-chirp 1.55-μm complex-coupled DFB lasers with a current-blocking grating
Author :
Chuang, Z.M. ; Wang, C.Y. ; Lin, W. ; Liao, H.H. ; Su, J.Y. ; Tu, Y.K.
Author_Institution :
Photonic Technol. Res., Chunghwa Telecom Co. Ltd., Taoyuan, Taiwan
Abstract :
Low-threshold current DFB lasers have been fabricated based on a complex-coupled structure with a current blocking grating. A threshold current as low as 5 mA was obtained, which enabled high temperature operation up to 105/spl deg/C. Asymmetric facet coatings were applied to obtain a high efficiency of 0.3 W/A. The strained InGaAsP MQW active region and the antiphase coupling has resulted in a low modulation chirping. By direct modulation of the device at 2.488 Gb/s and using optical amplifiers, we have demonstrated digital transmission over a 235 km-long standard single-mode fiber with a power penalty of 1.55 dB.
Keywords :
III-V semiconductors; chirp modulation; distributed feedback lasers; electro-optical modulation; gallium arsenide; gallium compounds; indium compounds; infrared sources; laser transitions; optical couplers; optical films; optical transmitters; quantum well lasers; /spl mu/m complex-coupled DFB lasers; 105 C; 2.488 Gbit/s; 235 km; 5 mA; InGaAsP; antiphase coupling; asymmetric facet coatings; complex-coupled structure; current blocking grating; current-blocking grating; digital transmission; direct modulation; high efficiency; high temperature operation; highly efficient; low modulation chirping; low-chirp; low-threshold current DFB lasers; optical amplifiers; power penalty; single-mode fiber; strained InGaAsP MQW active region; threshold current; very-low-threshold; Chirp modulation; Coatings; Couplings; Digital modulation; Gratings; Optical devices; Quantum well devices; Stimulated emission; Temperature; Threshold current;
Journal_Title :
Photonics Technology Letters, IEEE
