Optical multiplexer and demultiplexer

摘要

An optical multiplexer and/or optical demultiplexer for multiplexing and/or demultiplexing a plurality of wavelengths comprises a plurality of optical filters each of which transmits a predetermined wavelength and reflects other wavelengths, said optical filters being arranged so that an optical beam is transmitted or reflected via each optical filter in sequence in a zigzag fashion. A light source or light detector is provided behind each optical filter to project or receive a collimated optical beam. The angle of incidence when a beam is applied to an optical filter is small. And, another optical means is provided to connect the present optical multiplexer and/or demultiplexer with an outside optical fiber. The transmission wavelength of each optical filter is different from the others.