Patent ID: 7173713

Claim:
A sensor comprising: a ferrule, the ferrule having a bore formed therein, the ferrule having an end; a diaphragm attached to the ferrule, the diaphragm having an inside reflecting surface facing the end of the ferrule; a first optical fiber within the bore, the optical fiber having a first end; a second optical fiber, the second optical fiber having a first end and a second end, the first end of the second optical fiber being attached to the first end of the first optical fiber, the second end of the second optical fiber being spaced apart from the inside reflecting surface of the diaphragm, the second end of the second optical fiber and the inside reflecting surface of the diaphragm forming a Fabry-Perot cavity; wherein the first optical fiber has a first coefficient of thermal expansion; the second optical fiber has a second coefficient of thermal expansion, and the ferrule has a third coefficient of thermal expansion, the second coefficient of thermal expansion being selected to compensate for a difference between the first and third coefficients of thermal expansion.