OPTICAL INTEGRATED CIRCUIT

摘要

PURPOSE:To improve the characteristic of an optical integrated circuit by providing a groove to a part other than the optical waveguide part of a light guide layer and intercepting light which is not guided with the aid of the groove. CONSTITUTION:The optical integrated circuit has structure that the groove (a) is formed by scraping off the GaInAsP light guide layer 21 at the part between two parallel optical waveguides as a graphic shows. By forming the groove (a) with the aid of scraping off the GaInAsP light guide layer 21 in such a way, the light which is not guided is scattered at the scraped off part when it is passed through the GaInAsP light guide layer 21 even when a Mach- Zehnder light modulator 11 cannot be made according to a design and light from a semiconductor laser 10 is not well guided and bent at the Y branch point of the Mach-Zehnder light modulator 11. Thus, the value >=20db is always obtained as the on/off ratio of the Mach-Zehnder light modulator 11.