Dual directional wavelength demultiplexer

Claim 1

A fiber optic dual directional demultiplexer for tapping off predetermined portions of multiplexed optical energy from a single optical fiber and demultiplexing the optical energy comprising: a curved form for supporting an optical fiber and shaping a portion thereof to a predetermined segment of a circle; a single optical fiber mounted on said form and capable of transmitting light in both directions along its axis; means for affixing the optical fiber along a portion thereof to the curved portion of the form of a selected radius of curvature, the fiber and affixing means in the center section of the curved portion of the fiber being lapped and polished to a preselected depth of penetration into the fiber to develop a planar surface; prism means having two faces of predetermined opposed characterisitc angles affixed to said planar surface in contact with the optical fiber and affixed thereto by means of an optically transparent adhesive, each face being effective to receive light travelling in a corresponding direction in said fiber and coupled out of said fiber; light diffracting means formed on each of said prism faces positioned in the path of the coupled light exiting said fiber and effective to reflect and diffract signals incident thereto; and plural photosensitive means positioned adjacent said prism to respond selectively to different wavelengths of light directed from the light diffracting means.