Fiber Optic Remote Angular Position Sensor Including a Polarization Track

Abstract

A sensor for remotely detecting an angular position of a shaft rotatable within a frame includes: first means for generating collimated first, second, third, and polarized optical beams; second means positioned proximate to the first means for receiving and combining the first. second, third, and polarized optical beams into a composite optical beam having an intensity; and a code wheel fixedly mounted to the shaft and interposed between the first and second means. The code wheel includes first, 'second, and third channel mask patterns and a first polarizing filter positioned to transect the first, second, third, and polarized optical beams, respectively. Interaction between the code wheel and the light beams results in the composite light beam being encoded such that the angular position of the wheel is functionally related to the intensity of the composite opitical beam. The sensor further includes third means operably coupled to receive the composite optical beam for providing an output corresponding to the angular position of the code wheel.