Abstract

The principle of an optical-wavelength multiplexer/demultiplexer, in which the signals undergo repeated reflections from special filter elements that can be designed for any desired cross-talk ratio, is described. In theory, a cross-talk ratio of 60 dB should be easy to achieve. The insertion losses of these units can be quite small, allowing a number of filter elements designed for different wavelengths to be placed in series. The resulting device can provide simultaneous, multichannel two-way transmission. In a preliminary investigation of an experimental prototype, an insertion loss of 0.5 dB, a cross-talk ratio of 35 dB, and a wavelength separation of 0.05 μm were demonstrated. The multiplexer/demultiplexer is expected to have a long life and a high reliability. It is compact and should lend itself to low cost mass production.

© 1990 Optical Society of America