| 摘要 |
PURPOSE: To make an optical communication equipment small and light by leading the detection signal of each photo diode of a four-quadrant photodetector to an operational amplifier part and calculating the deviation of the incidence direction or laser light to each light reception part and using a part of photo diodes as a light reception element for communication. CONSTITUTION: In the four-quadrant photodetector, laser light received by light reception parts 1 to 4 is led to optical amplifiers 9 to 12 through optical fibers 5 to 8 and is amplified in the stage of light. Amplified signal light is led to photo diodes 13 to 16 and is converted to electric signals, and they are processed in an operation processing part 17, and deviation detection signals of laser light made incident on light reception parts 1 to 4 are outputted. A direction control mirror not shown in Fig. is driven by these deviation signals to correct the deviation of incident laser light, and thus, acquisition and tracking operation are performed. An optical signal for communication is detected in the photo diode 16 and is converted to an electric signal and is amplified by an amplifier and is demodulated by a demodulator and is received. |
