Abstract: An optical isolator maintains the intensity of light traveling therethrough in a forward direction, irrespective of the condition of polarization of the light, while substantially, preventing light having any condition of polarization from traveling therethrough in a reverse direction. The optical isolator generally includes first polarization apparatus to divide an incident light beam into two linearly polarized light beams having their directions of polarization perpendicular to each other, a non-reversible polarizing rotation element to rotate each of said linearly polarized light beams to form two rotated linearly polarized light beams and polarization converting apparatus which, in conjunction with a second polarization apparatus, synthesizes the two rotated linearly polarized light beams.

Abstract: The invention contemplates an improved light-mode separator for orientation in axially offset adjacency to an end of an optical fiber, in a plane perpendicular to the fiber axis; separate concentric regions of the separator about the fiber axis have different light-converging properties such that the convergence point for each light-converging region is (a) offset with respect to the convergence point for each remaining light-converging region, and is also (b) independently externally accessible for focused-energy utilization without masking interference with any other converging light from the separator.

Abstract: A multiplexed holographic recording system employs plural transparent positive pictures, each representing a different pictorial or video information content, which embody differing, unique pre-assigned spatial frequencies. A hologram is formed of the positive pictures, the reconstructed image from the hologram being identical in smoothed intensity distribution to a composite picture formed by superposition of the positive pictures.Spatial frequency filters are employed to remove, from the object beams transmitted through the positive pictures driving hologram formation, spatial frequency components assigned to other pictures. Accordingly, crosstalk between the multiplexed pictorial information is obviated.