The monitoring system disclosed herein comprises apparatus for transmitting a polarized and modulated light beam from a source at the one monitoring point and splitting the light beam into a plurality of beam portions having different spectral ranges or colors. Each color is directed through one or more transducers, positioned at the other monitoring point, which modify the polarization of the light beam portion. Each transducer is of a type such that the amount of birefringence depends upon the angle which the transducer is rotated about its sensitive axis from an initial position, and the transducer is substantially insensitive to rotations about any other coplanar axis. The beam portions of different colors are combined in a beam and reflected to analyzers adjacent the light source where they are again separated into colors and analyzed separately to determine the change in polarity due to birefringent action. A signal is produced which is a measure of the degree of angular displacement. This signal can be utilized to control servo motors for restoring the two monitoring points to their original relative positions. The analyzing of the portions of light beam is preferably accomplished at the first monitoring point where the beam source is positioned.
Aligning a stable ring resonator by the use of an inversion mechanism ins the resonator and a pair of anti-symmetric masks. Each mask has opaque and clear parts and the masks are anti-symmetric in that, in use, one mask is positioned so that its opaque and clear parts are anti-symmetric to the opaque and clear parts of the other mask when it is in position. One mask is placed between the radiation source and the beam splitter while the other mask is placed between the beam splitter and the focal plane on which the two beam portions created by the beam splitter focus. One beam portion is directly reflected from the beam splitter and the other portion is transmitted into the resonator and is inverted while following a beam path within the resonator before being outcoupled through the beam splitter in a much weakened state. Thusly positioned, the anti-symmetric masks have the effect to attenuating the intensity of the reflected beam portion, so that the relative intensities of the transmitted and the reflected beam portions are more equal when they arrive at the focal plane. This, in turn, makes the alignment of the two focal spots easy. When the two spots merge completely the ring resonator is aligned.
The present invention provides an object reflector detection system, in which laser beam is emitted toward an object reflector and reflection light beam is received to detect presence or absence and position of the object reflector, whereby there are provided a laser beam emitter and a reflection light beam detector, and further a laser beam emitter for emitting polarized irradiation light beam toward the object reflector, and a reflection light beam detector for detecting polarized reflection light beam from the object reflector, and the reflection light beam detector having a first detection means for detecting polarized reflection light beam from the object reflector, a second detection means for detecting polarized light beam different from the polarized reflection light beam from the object reflector and a reflection light beam detection circuit for identifying the object reflector based on comparison between output of the first detection means and output of the second detection means.
There is provided a surveying apparatus for detecting an object reflector (102) and measuring a distance from the object reflector (102) based on a luminous flux reflected by the object reflector (102) by irradiating a luminous flux toward the object reflector which varies a direction of polarization of reflected rays relative to that of incident rays. The surveying apparatus includes a light source section (106) for radiating the luminous flux as a luminous flux having a predetermined direction of polarization; an irradiating optical system (101) for irradiating the luminous flux from the light source section (106) toward the object reflector (102); a polarizing optical element (122) for dividing a polarized/reflected luminous flux of which direction of polarization has been varied when reflected by the object reflector (102); a first light-receiving section (124, 126) for receiving the polarized/reflected luminous flux divided by the polarizing optical element (122); a second light-receiving section (120) for receiving the reflected luminous flux reflected by the object reflector (102); a detecting section (104) for detecting the object reflector based on an output signal from the first light-receiving section (124, 126); and a distance measuring section (131) for measuring the distance from the object reflector (102) based on an output signal from the second light-receiving section (120).
The retro-encoded guidance system guides a flying object in its flight tod its destination by measuring and correcting the angular displacement of its actual trajectory from the straight line-of-sight to the destination. A beam of infrared light emanating from a beacon on the flying object is received and angularly encoded by retro-encoder located at the launcher prior to being returned to the missile. The incident beam and returned beam travel on optical paths that are parallel to each other but opposite in direction. The angular encoding is achieved by a reticle of the retro-encoder imparting frequency modulation to the incident beam, the degree and phase of the modulation depending on the location on the reticle on which the beam is incident.
The present invention provides an object reflector detection system, in which laser beam is emitted toward an object reflector and reflection light beam is received to detect presence or absence and position of the object reflector, whereby there are provided a laser beam emitter and a reflection light beam detector, and further a laser beam emitter for emitting polarized irradiation light beam toward the object reflector, and a reflection light beam detector for detecting polarized reflection light beam from the object reflector, and the reflection light beam detector having a first detection means for detecting polarized reflection light beam from the object reflector, a second detection means for detecting polarized light beam different from the polarized reflection light beam from the object reflector and a reflection light beam detection circuit for identifying the object reflector based on comparison between output of the first detection means and output of the second detection means.
