| 摘要 |
There are provided a light source outputting a light having a first wavelength; a terminal unit including a directional coupling section having first and second optical waveguides, in which a first surface is formed on one end of the directional coupling section, and first and second optical input/output units respectively connected to the first and second optical waveguides are connected to the other end of the directional coupling section, and the light having the first wavelength is input from one end, and the light having the second wavelength is input and output from the first optical input/output unit; and an optical filter provided between a first end surface and the light source for passing the light having the first wavelength and for reflecting the light having the second wavelength. The light having the first wavelength is output from the second optical input/output unit, and the light having the second wavelength is input or output. The directional coupling section is designed to have the complete coupling length for the light having the first wavelength, and have a half length of the complete coupling length for the light having the second wavelength. Anoptical amplifier reduces the loss generated in the process from the pump light source to the rare-earth doped optical fiber so that the reduction of the gain of the rare-earth doped optical fiber can be prevented.
|
