Optical wavelength division multiplexing/demultiplexing system

A wavelength-division system comprising a radiation transmission planar waveguide provided with a single collimating lens and a single focusing lens and with a periodic radiation transmissive passive diffraction grating incorporating a multiplicity of radiation reflecting elements in spaced array preselected, and of length sufficient for Bragg diffraction to occur at the center wavelength in the material as defined by the following formula:

• ##EQU16## and the length is sufficiently short to permit a large angular scanning range as defined by the following formula ##EQU17## wherein 1is the length of each radiation reflecting element
• .lambda.oc is the center wavelength in the free space
• n is the index of refraction of the wave guiding material at .lambda.oc
• .LAMBDA.is the regular interval of the spaced radiation reflection elements,
• .DELTA..theta..sub.3 is the angular scanning range
• said passive diffraction grating being in demultiplexing service, to separate, via the wavelength-dependent angular dispersion of said diffracting grating, into individual entities an optical signal input constituting a multiplicity of coherent radiation signals of different characteristic wavelenghts transmitted simultaneously via said radiation transmissive planar waveguide and, in multiplexing service, to consolidate, via angular dispersion, a multiplicity of coherent radiation signals from optical sources individually introduced to said transmissive diffraction gating via said radiation transmissive planar waveguide along angular courses substantially coincident with the angular courses taken by individual radiation signals of corresponding wavelengths exiting said transmissive diffraction grating in said demultiplexing service, and means directing said signals to dedicated receptors.