Integrated optical device with improved isolation between the semiconductor laser and the photodetectors

Claim 1

An optical recording and reproducing head for a laser memory disk, comprising: a substrate (1); a waveguide layer (3) formed over a main surface of said substrate; a semiconductor laser (4) provided at an end of said waveguide layer for injecting laser beams into said waveguide; a focusing grating coupler (6) formed on said waveguide layer for focusing said injected laser beams on said disk and introducing beams reflected back from said disk into said waveguide; beam splitter means (5) formed on said waveguide layer between said semiconductor laser and said focusing grating coupler, for bisecting said reflected beams into two distinct directions, each distinct direction being at a prescribed acute angle; photodetector means (10) for converting said bisected beams into electrical signals; optical isolator means (17, 18) formed between said semiconductor laser and said photodetector means comprising at least one groove of a prescribed length which is cut with at least partial depth into said waveguide layer along each side of said semiconductor laser.