PURPOSE: To lessen the coupling loss with optical fibers in a distribution feedback type semiconductor laser by a method wherein the laser is made into a structure, wherein the divergence angle of beams is smaller and the outgoing beam mode is brought nearer to a circular one.
CONSTITUTION: A layered formation; which consists of a P type contact layer 2, P type antimeltback layer 3, and active layer 4, an N- type waveguide layer 5 and an N type substrate 6; is formed, and N type buried layers 8 and P type buried layers 9 are formed on both sides thereof. After these layers are formed, the top surface of the P type contact layer 2 is masked with a resist, etc., leaving the wedge-shaped open part intact, and an almost conical cavity is formed by performing an etching for forming the cavity by epitaxially growing a buried and enlarged waveguide path 10. Lastly, a P-side electrode 1 and an N-side electrode 7 are respectively formed on the top surface and the bottom surface. The front 11 of the buried and enlarged waveguide path 10 is an outgoing end.
NISHIWAKI YOSHIKAZU
MATSUOKA HARUJI
NISHIURA YOUZOU
OKAMOTO KENJI
