Abstract: A dual wavelength optical coupler is disclosed which provides either bidirectional or unidirectional communication at different wavelengths over a single fiber. The coupler utilizes a dichroic filter and a set of three lenses to achieve dual wavelength communication. Additional blocking filters may be incorporated to decrease the degree of optical crosstalk present in the system.

Abstract: An optical device which diverts light from one transmission element (e.g. 21) to another (e.g., 22, 23 and 24) and a method of manufacture are disclosed. The device includes a pair of focusing elements (10 and 11) such as graded index of refraction lenses separated by a pair of at least partially reflecting elements (12 and 13). Optical transmission elements are placed adjacent to the surfaces (17 and 20) of the focusing elements opposite the reflecting elements. The reflecting elements are placed at an angle to each other and the transmission elements positioned to achieve efficient light coupling. The reflecting elements can then be fastened to each other by an appropriate adhesive (14).In specific embodiments, the device may function as a multiplexer/demultiplexer for light having three or more wavelengths, or as an asymmetric four-port coupler.