| 摘要 |
PROBLEM TO BE SOLVED: To provide inexpensive equipment where an angular range of automatic tracking is extended with a simple configuration and an automatic tracking function with a fast response is provided. SOLUTION: A transmission signal is received from an input terminal 38, amplified by an amplifier 37, converted into an optical signal by a light emitting element 34, passes through an optical transmission system 33 and a polarized light beam splitter 32 and is sent to opposite equipment in the form of a light beam via a moving mirror 31 and a transmission/reception lens system 30. On the other hand, a received signal from the opposite equipment is made incident from the transmission/reception lens system 30, reflected in the moving mirror 31 and reflected in a stuck surface of the polarized light beam splitter 32 and collected by a signal light detector 36. Then the electric signal converted from the optical signal by the photodetector 36 is amplified by an amplifier 39, and outputted from an output terminal 40 as a received signal. Furthermore, the signal of a detection circuit 41 is given to a control circuit 42, where the signal is used for detecting received power, and the control circuit 42 gives a drive signal to variable mirror drivers 43a, 43b based on the signal. Simultaneously an output signal from the detection circuit 41 is used for automatic gain control of the amplifier 39. |
