Utilization of optical-frequency carriers for low- and moderate-bandwidth channels

Recent advances in solid-state optical-frequency sources and detectors and low-loss optical fibers make feasible the consideration of optical communication systems for low- and moderate-bandwidth channels (a few kHz to, say, 100 MHz). This paper explores the use of optical-frequency carrier systems for transmission over such channels. Analog intensity modulation, pulse position modulation, delta modulation, and pulse code modulation are considered. This paper is intended to be tutorial in nature.