Low-loss coupling of 980 nm GaAs laser to cleaved single mode fiber

In conclusion, we used waveguide engineered GaAs-AlGaAs-InGaAs laser diodes at 980 nm with reduced divergence at 15.1 degrees and symmetric beams. We achieved a record low coupling loss of only -1 dB into single mode fiber with a relaxed alignment tolerance. The achieved -1 dB coupling efficiency demonstrates a better than two fold improvement over the coupling efficiency from a conventional laser diode to a cleaved fiber.