PHASE MODULATOR, PHASE MODULATOR ASSEMBLY, AND PHOTOSENSOR
First Claim
1. A phase modulator comprising a cylindrical or columnar actuator whose body has a characteristic of inducing mechanical vibration and a polarization preserving fiber having two light propagation axes that are orthogonal to each other, the fiber being wound around the actuator in such a manner to receive mechanical stress caused by the mechanical vibration in directions each of about 45 degrees with respect to the two light propagation axes.
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Accused Products
Abstract
The present invention provides a photosensor that uses a phase modulation technique for optical detection and conducts a highly accurate measurement. The photosensor uses a phase change difference of light propagated through a polarization preserving fiber with respect to tensile stress and employs proper polarization preserving fibers for a phase modulator 10, light-transmitting polarization preserving fiber 23, and coil-shaped polarization preserving fiber 30, to achieve a highly accurate measurement.
5 Citations
23 Claims
- 1. A phase modulator comprising a cylindrical or columnar actuator whose body has a characteristic of inducing mechanical vibration and a polarization preserving fiber having two light propagation axes that are orthogonal to each other, the fiber being wound around the actuator in such a manner to receive mechanical stress caused by the mechanical vibration in directions each of about 45 degrees with respect to the two light propagation axes.
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3. A phase modulator comprising a cylindrical or columnar actuator whose body has a characteristic of inducing mechanical vibration and a polarization preserving fiber having two light propagation axes that are orthogonal to each other, the fiber being wound around the actuator in such a manner to receive mechanical stress isotropically with respect to the two light propagation axes.
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4. A phase modulator comprising a cylindrical or columnar actuator whose body has a characteristic of inducing mechanical vibration and a polarization preserving fiber having two light propagation axes that are orthogonal to each other, the fiber being wound around the actuator at a predetermined twist rate.
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12. A photosensor comprising a photo-sensing unit to measure a measuring physical quantity, a signal processing unit to calculate a specified physical quantity according to a light signal from the photo-sensing unit, and an optical fiber to optically connect the photo-sensing unit and signal processing unit to each other, the optical fiber being a polarization preserving fiber having two light propagation axes each of which propagates light,
the polarization preserving fiber being one that demonstrates a small change in a propagation constant difference between the two light propagation axes with respect to tensile stress.
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21. A photosensor including a photo-sensing unit to measure a measuring physical quantity, a signal processing unit to calculate a specified physical quantity according to a light signal from the photo-sensing unit, and an optical fiber to optically connect the photo-sensing unit and signal processing unit to each other, the photosensor comprising:
other than a phase modulator, a coil-shaped optical element formed of a polarization preserving fiber that demonstrates a small change in a propagation constant difference between two light propagation axes of the fiber with respect to tensile stress. - View Dependent Claims (22, 23)
Specification