| 摘要 |
PURPOSE:To make possible miniaturization, simplification and economization and to improve mass productivity and reliability by constituting an optical multiplexer and demultiplexer on a three-dimensional optical waveguide and uniting functional devices such as semiconductor light emitting element and photodetector to one body. CONSTITUTION:The width W of the optical waveguide 4 is determined at the width at which the light signal of wavelengths lambda1-lambda3 is guided. Said width is made gradually smaller so as to taper from an input and output end face 15 toward the right side. A single mode optical fiber is connected to the face 15 and the light signal of the wavelengths lambda2, lambda3 is propagated from an arrow 1 direction and is made incident on the inside of the waveguide 4. The light signal of the wavelength lambda1 is transmitted in the optical fiber toward an arrow 2 direction. The wavelengths are related like lambda3>lambda2>lambda1 in this case. The width W3 of the optical waveguide in the part 6 is so set as to satisfy the equation (2), then if the light signal of the wavelengths lambda2, lambda3 is made incident on the inside of the waveguide 4, the light signal of the wavelength lambda3 satisfies the cut off condition of the optical waveguide in the part 6 and is radiated in the form of a leak mode like an arrow 9. The light is then condensed by a lens 11 and the light signal of the wavelength lambda3 is detected by the photodetector 13. |
