| 摘要 |
PURPOSE:To improve condensing efficiency and to stabilize the characteristic of a filter by disposing optical fibers near lenses and filters between prisms and maintaining a specified angle relative with the incidence of rays. CONSTITUTION:Light having three wavelengths lambda1, lambda2, lambda3 is transmitted to an optical fiber, is made incident to a lens 20 and is made into parallel light by a prism 23 when a titled device is used as a demultiplexer. A filter 14 is placed on the face (c) with inclination at theta (<=20 deg.) to an optical axis 25 so that the lambda1 is reflected to pass through the filter 12 on the face (b) and to enter the fiber 2 via a lens 21. The light lambda2, lambda3 transmit through the filter 14 to advance through the inside of a prism 24 and the lambda2 is reflected by a filter 13 inclining at epsilon deg.. Therefore the lambda2 advances reverse through the prisms 24, 23 and the lens 20 and enters an optical fiber 5. On the other hand, the lambda3 transmitting through the filter 13 is condensed by a lens 22 and enters an optical fiber 4. The incidence and exit of the lambda1-lambda3 are reverse in the case of using the device as a multiplexer and a light emitting element is provided at the terminals of the fibers 2, 4, 5 in place of a photodetector. |
