50 mW stable single longitudinal mode operation of 780 nm GaAlAs DFB laser

The achievement of stable single-longitudinal-mode (SLM) operation of a 780 nm GaAlAs distributed-feedback (DFB) laser with output power as high as 50 mW is discussed. The laser employs the buried twin-ridge substrate structure which allows stable fundamental spatial mode operation even at high power levels. The designed coupling strength is 0.5 from the viewpoint of obtaining a low operation current at 50 mW. SLM operation was maintained for powers up to 50 mW at room temperature and in the temperature range from -17 to 37 degrees C at 50 mW. The maximum power attained was 62 mW.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>