A Review of Coherent Optical Communication

Coherent optical communications for fiber transmission media are being seriously considered for both commercial and military applications. A variety of modulation schemes have been examined both in the laboratory and in field trials to verify the feasibility of this transmission technique using optical fibers. This paper will review coherent transmission techniques including optical heterodyne receiver concepts, implementation considerations, and device requirements. Some generic applications of these techniques to military communication systems will then be discussed.