Multiple FM-video signal transmission through optical fiber for use in security

Described is a dual FM video signal transmission system with an optical fiber for use in monitoring pictures for security purpose. Each video signal from each video camera is modulated by the FM scheme actualized by using a VCO operating at 30 MHz or 50 MHz, and the modulated RF video signal is sent to the optical fiber through the electrical-to-optical converter consisting of an LED at 850 nm. The optical FM video signal is received by using the optical-to-electrical converter. Each received FM video signal is demodulated by using a PLL to reproduce the video signal. The camera mount attitude for one of a pair of video cameras can be adjusted by the optical control signal issued from the monitoring site.<
>