Emission Characteristics of Surface Second-Order Metal Grating Distributed Feedback Semiconductor Lasers

Abstract

A DFB laser with surface second-order metal grating emitting around 940nm is fabricated, which can achieve high power 385mW, spectral linewidth (FWHM) 0.5nm and lateral far field angle (FWHM) 2.7º at CW 1.5A, and operate in a stable longitudinal mode. Extended abstractIn order to obtain high-power semiconductor lasers with stable operation in a single longitudinal mode and improve the characteristics of the output beam, a distributed feedback laser with surface second-order metal grating emitting around 940nm is fabricated. The characteristics of devices with surface second-order metal grating and without grating are tested and compared. Results indicate that devices with grating achieve powers as high as 385mW, spectral linewidth (FWHM) less than 0.5nm, central-wavelength shift only 4.2nm/A (CW), and lateral far field angle (FWHM) less than 2.7º at CW 1.5A, and operate in a stable longitudinal mode, while devices without grating achieve high powers (600mW), but larger lateral far field angle (7.2º) and spectral linewidth (1.3nm), and operate in multimode. In conclusion, DFB lasers with surface second-order metal grating can operate in a stable longitudinal mode, achieve high powers with small lateral far field angle and spectral linewidth, and improve the characteristics of the output beam.

Suppressing longitudinal spatial hole burning with dual assisted phase shifts in pitch-modulated DFB lasers

“…Distributed feedback (DFB) semiconductor lasers have been widely used in optical communication systems [1][2][3][4][5]. They operate in single longitudinal mode (SLM) and have highly controllable lasing wavelength [6][7][8][9][10]. However, the conventional DFB lasers working at high injection currents often become multimode.…”