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

摘要

An optical head for a laser memory disk in accordance with the present invention containing a substrate (1); a waveguide layer (3) formed over a main surface of the substrate; a semiconductor laser (4) provided at an end of the waveguide layer for injecting laser beams into the waveguide; a focusing grating coupler (6) formed on the waveguide layer for focusing the injected laser beams on the disk and introducing beams reflected back from the disk into the waveguide; beam splitters (5) formed on the waveguide layer between the semiconductor laser and the focusing grating coupler, for bisecting each of the reflected beams at a prescribed acute angle; photodetectors (10) for converting the bisected beams into electrical signals; optical isolators (17, 18) formed between the semiconductor laser and the photodetectors.