Fabry-perot optical sensing device for measuring a physical parameter
First Claim
1. An optical sensing device for measuring a physical parameter, to be connected to a light source for generating a multiple frequency light signal having predetermined spectral characteristics, said device comprising:
- a) a Fabry-Perot interferometer through which the light signal is passed, said Fabry-Perot interferometer including two semi-reflective mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by said physical parameter and which cause said spectral properties of the light signal to vary in response to said physical parameter, said Fabry-Perot interferometer being provided with at least one multimode optical fiber for transmitting the light signal into said Fabry-Perot cavity and for collecting at least a portion of the light signal outgoing thereof;
b) optical focusing means for focusing said at least a portion of the light signal; and
c) a Fizeau interferometer through which said focused light signal is passed, said Fizeau interferometer including optical wedge means forming a wedge-profiled Fizeau cavity from which exits a spatially-spread light signal indicative of said transmittance or reflectance properties of said Fabry-Perot interferometer;
whereby said physical parameter can be determined by means of said spatially-spread light signal.
1 Assignment
0 Petitions
Accused Products
Abstract
The optical sensing device and the method thereof are for measuring a physical parameter. The device is to be connected to a light source which generates a multiple frequency light signal having predetermined spectral characteristics. The device comprises a Fabry-Perot interferometer through which the light signal is passed, an optical focusing device for focusing at least a portion of the light signal outgoing from the Fabry-Perot interferometer, and a Fizeau interferometer through which the focused light signal is passed. The Fabry-Perot interferometer includes two semi-reflecting mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by the physical parameter and which cause the spectral properties of the light signal to vary in response to the physical parameter. The Fabry-Perot interferometer is provided with at least one multimode optical fiber for transmitting the light signal into the Fabry-Perot cavity and for collecting the portion of the light signal outgoing thereof. The Fizeau interferometer includes an optical wedge forming a wedge-profiled Fizeau cavity from which exits a spatially-spread light signal indicative of the transmittance or reflectance properties of the Fabry-Perot interferometer. The physical parameter can be determined by means of the spatially-spread light signal.
186 Citations
24 Claims
-
1. An optical sensing device for measuring a physical parameter, to be connected to a light source for generating a multiple frequency light signal having predetermined spectral characteristics, said device comprising:
-
a) a Fabry-Perot interferometer through which the light signal is passed, said Fabry-Perot interferometer including two semi-reflective mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by said physical parameter and which cause said spectral properties of the light signal to vary in response to said physical parameter, said Fabry-Perot interferometer being provided with at least one multimode optical fiber for transmitting the light signal into said Fabry-Perot cavity and for collecting at least a portion of the light signal outgoing thereof; b) optical focusing means for focusing said at least a portion of the light signal; and c) a Fizeau interferometer through which said focused light signal is passed, said Fizeau interferometer including optical wedge means forming a wedge-profiled Fizeau cavity from which exits a spatially-spread light signal indicative of said transmittance or reflectance properties of said Fabry-Perot interferometer; whereby said physical parameter can be determined by means of said spatially-spread light signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. An optical sensing method for measuring a physical parameter, comprising steps of:
-
a) generating a multiple frequency light signal having predetermined spectral characteristics; b) passing the light signal in a Fabry-Perot interferometer including two semi-reflective mirrors substantially parallel to one another and spaced by a given distance so as to define a Fabry-Perot cavity having transmittance or reflectance properties which are affected by said physical parameter and which cause said spectral properties of the light signal to vary in response to said physical parameter, the light signal being transmitted into said Fabry-Perot cavity with at least one multimode optical fiber, and at least a portion of the light signal outgoing from said Fabry-Perot cavity being collected with said at least one optical fiber; c) focusing said at least a portion of the light signal; and d) passing the focused light signal through a Fizeau interferometer for converting the focused light signal into a spatially-spread light signal indicative of said transmittance or reflectance properties of said Fabry-Perot interferometer; whereby said physical parameter can be determined by means of said spatially-spread light signal. - View Dependent Claims (21, 22, 23, 24)
-
Specification