Variable ratio beam splitter and beam launcher

Abstract

A continuously variable ratio beam splitter and beam launcher for dividing an input light beam, particularly a polarized coherent light beam, into two output beams, within a broad intensity variation range between the beams which may approach zero to 100%, without loss of polarization, comprises an optical array on a support adjustably mounted on a frame; the optical array includes an optical divider aligned with a penta prism that effectively couples the optical divider to one side surface of a right angle output prism. The optical divider and the output prism launch two output beams, based on division of the light from the input beam impinging on the optical divider. Variation of the intensity ratio of the output beams is accomplished by rotating the optical array support about a pivot point aligned with the input beam so that the input beam strikes the optical divider at different angles. Each output beam is picked up by an optical fiber or like transmission element previously located at a fixed position on the frame of the device. The output beams are always aligned along essentially the same output paths, regardless of changes in the angular orientation of the optical array, so that the amplitude ratio between the two output beams can be changed merely by rotational adjustment of the optical array without refocusing or adjusting other components of the device.