Gaussian patterned contacts for improved beam stability of 1.55-μm tapered lasers

A Gaussian lateral current-injection profile is approximated by a quasi-random pattern of electrically conducting and insulating regions. This pattern is used for the p-type contact in a laser with a 2.1-mm-long tapered gain region and operating near 1.55-μm wavelength. Lasers with improved stable single lateral modes are obtained with Strehl ratios up to 0.85 for current up to 4.0 A and output power over 1.0 W. Power over 0.5 W can be coupled into a single-mode optical fiber with a cylindrical microlens attached to the output facet to remove the astigmatism of the laser.