Wide Field of View Remote Laser Position Sensor.
DEPARTMENT OF THE ARMY WASHINGTON DC
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A laser position sensor system is described for viewing a wide field of view for detecting the angular position of a remote laser. A laser beam directed toward the sensor from any position within a 90 deg circular field-of-view can be detected to a positional accuracy of less than 0.1 deg in a two-axis coordinate system. The system utilizes two parallel sensors having field-of-view optics that compress the field-of-view. The compressed output from each optics is directed through a polarizer and filter to a phase shifter. The phase shifter, a pair of birefringent crystals, encodes the angle of incidence of the laser beam as a phase shift between the two components of the polarized input beam. These components, the e-ray and the o-ray travel different paths through the phase shifter. Subsequently, an analyzer such as a Wollaston prism decomposes the beam into two linear components. These components are condensed through a reimager lens and coupled to a pair of intensity detectors. The detector outputs from each sensor can then be combined to provide a normalized signal proportional to a trigonometric function of the angle of incidence of the laser beam, indicative of its position in space.
- Lasers and Masers
- Optical Detection and Detectors