PURPOSE: To make it possible to emit an amplified light signal outside of a substrate by optically coupling the light signal propagating in an optical waveguide to a semiconductor light emitting element and putting this semiconduc tor light emitting element into a light emitting state.
CONSTITUTION: The optical waveguide 4 composed of a core layer 2 and a clad layer 3 is formed on the substrate 1. A semiconductor laser 10 is so fixed onto such optical waveguide 4 (core layer 2) that the semiconductor substrate surface is brought into contact therewith. The light refractive index of the semiconductor substrate of the semiconductor laser 10 is set higher than the optical refractive index of the optical waveguide 4. As a result, the light signal propagating in the optical waveguide 4 is optically coupled to the semiconductor laser 10 of the high light refractive index arranged thereon. Further, laser oscillation is generated by the light signal entering from the optical waveguide 4 and the laser beam is emitted in the surface direction when a bias current to the extent of obviating the oscillation is kept passed between electrodes. Namely, the light signal amplified in the light intensity is emitted outside of the substrate.
YAMADA YASUBUMI
MINO SHINJI
YANAGISAWA MASAHIRO
