| 摘要 |
PURPOSE:To reduce loss by equalizing size and price in a reception exclusive module or a transmission exclusive module. CONSTITUTION:Only one single-wavelength photo-detector having structure close to a GaAs/GaAlAs group DH junction LED is used as an optical semiconductor element 7 for transmission and reception, and the photo-detector is given both functions of light reception and emission. When forward voltage operating the element 7 as a light-emitting device is applied to the element 7 from a power circuit 8 for changing over transmission and reception, the element 7 functions as the light-emitting device. When a signal for transmission is applied to the element 7 from a signal processing circuit 9 for transmission, the signal is converted into light, and output to a fiber 1. When reverse voltage operating the element 7 as a photo-detector is applied to the element 7 from the power circuit 8, the element 7 functions as the photo-detector. The signal output from the fiber 1 is converted into an electric signal by the photo-detector. The received signal is input to a signal processing circuit 10 for reception and processed. Accordingly, single-wavelength light-reception-emission is enabled in the single element. |
