| 摘要 |
The present invention relates to an optical upconverting or downconverting gain or loss modulating mixer and a receiver for subcarrier optical communication systems using the mixer. The optical mixer can be formed, for example, from an optical amplifier (10) including a semiconductor laser chip comprising p-n junction with an active region channel formed along the junction. An optical signal (L(t)) received from the communication system is directed into one end of the channel, and a combination of a D-C bias signal (25) and a local oscillator signal (27) is concurrently impressed on the chip to gain-modulate the received optical signal and produce an upconverted or downconverted output signal. In the receiver (11), the upconverted or downconverted output signal from the gain-modulated optical amplifier is detected by a photodetector (12), amplified if necessary, filtered and then demodulated before transmission to the output utilization device. A loss modulator (30) provides similar optical mixing but does not provide a gain to the output signal. |
