| 摘要 |
A wideband optical link, e.g. for 8 TV channels or a block of stereo audio channels uses a highly linear VCOO (1) to which the multiplex input signal is applied. The VCO output is applied to a mixer (2) where it is mixed with the signal from an oscillator (3). The mixer output goes to a filter (4) which passes the desired mixer's sideband, in this case the lower sideband, and this, via amplifiers (5) and limiter (6) controls the laser (7) whose output is applied to an optical fibre. Thus the highly linear VCO enables a laser of relatively poor linearity to be used. At the receiver (Fig. 2) the signal from an optical receiver (10) goes via a filter (11) to another mixer (12), whose output is filtered (14) to pass the desired mixer side band. This then goes via a differential demodulator (15-16-17) to an output filter (18), the output of which is the receiver's output. <IMAGE> |
