Tunable and high-power semiconductor laser with good beam quality in optical-communication band

Abstract

High power and good beam quality are desired for semiconductor lasers in many applications. We propose a new type of broad area laser diodes that is capable of emitting good beam quality, high power and broadband tuning. The new type of laser diodes is fabricated with a broad-area waveguide that is oriented at an angle from the facet normal. This device does not require the DFB structure, so the fabrication is much simpler. The L-I curves, spectra, near-field patterns and far-field patterns of the angled broad-area waveguide laser diode are measured. The direction of the far field pattern along the facet normal for the device operated above the threshold current indicates that the light path is not along the waveguide direction. As the laser diode is inserted in a grating-loaded external cavity, it is tunable from 1280nm to 1315nm with output power up to 1.4 watt at 8Amp. The beam quality is good and the near field has negligible filamentation.