Circular, narrow beam emission of 1.3-µm surface-emitting laser with monolithically-integrated InP lens for direct fiber coupling

Circular, narrow beam emission of a lens-integrated surface-emitting laser operated at 1.3-mum wavelength was demonstrated. The laser consists of a distributed feedback laser cavity monolithically integrated with an etched 45deg total reflection mirror and an etched InP lens. The profile of the etched InP lens was estimated to be a highly symmetrical parabolic shape that is ideal for the collimation of a Gaussian beam. A fabricated lens-integrated surface-emitting laser exhibited a circular, narrow far-field pattern with full-width at half-maximums of 3.9deg times 3.5deg. A highly efficient direct coupling to a single-mode fiber with a coupling efficiency of - 2.7 dB was also confirmed.