High Spectral Purity High-Power GaSb-Based DFB Laser Fabricated by Nanoimprint Lithography

The development of single-mode distributed feedback (DFB) lasers emitting high output powers in a broad wavelength range from 1980 to 2035 nm is reported. A unique feature of the development is the fabrication of lateral feedback gratings by nanoimprint lithography. We have varied a wide range of design parameters and studied their effect on the performance of the laser. The best uncoated devices exhibited a side-mode suppression ratio as high as >50 dB at output powers in excess of 14 mW. Moreover, a tuning range of over 12 nm was measured. After coating the facets with dielectric mirrors, the laser diodes could deliver an output power of more than 25 mW. In this letter, we prove the suitability of nanoimprint lithography to the fabrication of GaSb-DFB laser diodes by demonstrating the state-of-the-art devices made using imprint lithography.