Optical sensors utilizing multiple reflection
First Claim
1. A sensor for a physical property, comprising:
- a light source;
light transmitting means for communicating with said light source, said light transmitting means comprising a row of optical fibers disposed between a reflecting means for multiply reflecting light provided from said light transmitting means; and
across a sensitive material means connected to said reflecting means whereby said reflecting means and said sensitive material means are affected by a physical quantity or property causing modulation of said multiply reflecting light wherein said optical fibers are arranged in a polymer block such that the optical fibers are suspended in said block above said sensitive material means and in isolation from said reflecting means and sensitive material means so that said optical fibers remain stationary when said sensitive material means are subjected to said physical quantity or property.
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Accused Products
Abstract
An improved method and apparatus for optically sensing and measuring physical quantities such as magnetic fields, electrical fields, mechanical strain, temperature, sound and pressure. The apparatus aspects of the invention involve a sensor structure consisting of a sandwich of magnetostrictive, piezoelectric or other materials sensitive to the physical quantity measured which are spaced apart by two opposed parallel reflecting surfaces located on opposing sides of the sensitive material. The reflecting surfaces can include an array of plane mirrors, diffraction gratings, curved mirrors, or retro-reflecting spheres. In its method aspects, multiple optical reflections between the two surfaces provide a magnified optical phase shift when the shape of the slab that is sensitive to changes in the applied field causes mechanical strains in the material. The changed optical signal can be measured by a suitable measurement device such as an interferometer for phase comparison with a diffraction reference pattern. Alternative embodiments include providing multiple sensors in a sandwich type structure in order to increase measurement sensitivity and accuracy.
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Citations
29 Claims
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1. A sensor for a physical property, comprising:
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a light source; light transmitting means for communicating with said light source, said light transmitting means comprising a row of optical fibers disposed between a reflecting means for multiply reflecting light provided from said light transmitting means; and
across a sensitive material means connected to said reflecting means whereby said reflecting means and said sensitive material means are affected by a physical quantity or property causing modulation of said multiply reflecting light wherein said optical fibers are arranged in a polymer block such that the optical fibers are suspended in said block above said sensitive material means and in isolation from said reflecting means and sensitive material means so that said optical fibers remain stationary when said sensitive material means are subjected to said physical quantity or property. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 29)
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28. A multiple sensor responsive to a physical quantity or property to be evaluated, comprising:
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light transmitting means for receiving light from said light source and for transmitting light from one sensor to an adjacent sensor; reflecting means for multiply reflecting said transmitted light in each of multiple sensor layers; and sensitive material connected to said reflecting means and for spacing said reflective means apart whereby said sensors are formed into a multi-layered sandwich where each layer provides a separate multiply reflective row of elements.
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Specification