Efficient Coupling of a Semiconductor Laser to an Optical Fiber by Means of a Tapered Waveguide on Silicon.

A Si sub 3 N sub 4 core waveguide, matched to a laser mode, is adiabatically tapered into a SiO sub 2 :P core waveguide, matched to a fiber mode. When used to coule the light from a semiconductor laser into an optical fiber, a loss of 3.1 dB is obtained, compared to a loss of 4.5 dB obtained with a lensed fiber.