Multiple channel multiplexer/demultiplexer devices

摘要

Multiple channel optical multiplexing/demultiplexing devices that utilize only a single constant, non-variable wavelength-selective optical interference filter have many advantages. The wavelength-selective optical filter is a conventional fixed wavelength optical interference filter having an angle shift property wherein the wavelength-selectivity changes with changing angles of incidence upon the filter. Because such filters are transparent to a different center wavelength depending on the angle of incidence of a light beam, multiplexing/demultiplexing is achieved by varying the angle of incidence of the light beam upon a single, constant and non-variable optical interference filter. Many different systems can be designed to transmit a light beam at multiple varied angles of incidence upon a single interference filter. Two such exemplary systems utilize a multiple-reflection chamber adapted to transmit a light beam at successively varied angles of incidence upon a single interference filter.