Several, multi-video channel, transmission methods using optical fibers have been demonstrated. These use an LED or laser light source and can be either analog or digital. The current limitation on multiple channel analog transmission is light source linearity. Several methods of improving linearity are being developed. At the high signal levels needed for amplitude modulated multiple channel video transmission PIN diodes are the preferred receiver. At present, 12 channel, analog transmission using a laser has been achieved over a single fiber for a length of one kilometer.
F. W. Dabby,
R. B. Chesler,
"Multiple Video Channel Transmission On A Single Optical Fiber", Proc. SPIE 0139, Guided Wave Optical Systems and Devices I, (13 July 1978); doi: 10.1117/12.956241; https://doi.org/10.1117/12.956241