Broad-area and MOPA lasers with integrated grating components for beam shaping and novel functions

Abstract

The work of the authors' group on monolithic integrated in-plane semiconductor lasers using grating components are reviewed and the recent development is reported. The grating components provide not only feedback for lasing but also novel functions such as output beam shaping and wavelength tuning. The design and fabrication of the grating components in semiconductor waveguide are outlined, and the area-selective quantum-well disordering by impurity-free vacancy diffusion is described as an effective technique to reduce the absorption loss in the passive waveguide. Then, device description, design, fabrication and experimental results of integrated master oscillator power amplifier (MOPA) lasers, high-power tunable extended-cavity lasers, and a broad-area angled-grating distributed Bragg reflector (DBR) lasers using InGaAs/AlGaAs GRIN-SCH-SQW structures are presented. All the lasers have integrated beam forming grating coupler, and allow implementation of compact and stable lensless modules that emit a collimated output beam.