High-efficiency fiber-coupled module based on multi-single emitter photonic-band-crystal laser diodes

Abstract

High-efficiency, high-power and high-brightness, fiber-coupled modules based on semiconductor laser diodes have been important sources in many fields, such as fiber laser pumping, material processing and defense applications. The coupling efficiency of fiber-coupled module has been limited due to the large vertical divergent angle of conventional semiconductor laser diodes. We present a high coupling efficiency module by using photonic-band-crystal (PBC) laser diodes with narrow vertical divergent angle. Fourteen PBC single-emitter laser diodes are combined into a fiber with core diameter of 200 μm and numerical aperture (NA) of 0.22. A high and stability coupling efficiency of 88% and peak otuput power of 47W with the injection current of 5 A are obtained. A comparison with the coupling efficiency of conventional laser diodes module is also presented. And there is a 5% increase of fiber-coupled efficiency based on PBC laser diodes module compared to conventional semiconductor laser diodes module.