| 摘要 |
According to one embodiment of the invention, the optical security system consists of a first laser beam generation and feedback signal receiving station on one end of the security zone and a second laser beam receiving and feedback signal transmitting station on the other end of the security zone. The first station consists of a laser source that generates a modulated low-divergence laser beam and a first optical signal receiver. The second station consists of a second optical signal receiver that receives the aforementioned modulated low-divergence laser beam emitted from the laser source and a feedback optical signal transmitter which is connected to the aforementioned second optical signal receiver via a signal processing unit which codes the received signal and forms it into a feedback signal to be sent to the first optical signal receiver of the first station from the transmitter of the second station. In the system of the second embodiment the feedback signals are in the form of IR, MW, or RF signals. The intruder is detected by comparing changes in the codes of direct and return signals.
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