Sensors for measuring pressure and temperature
A Fabry-Pérot sensor assembly includes an optical element defining a Fabry-Pérot optical cavity therein. A sensor ferrule is affixed to the optical element. The sensor ferrule is configured to physically connect to an optical fiber, aligning the optical fiber optically with the cavity. The optical element includes a LaGd doped hafnium or zirconium oxide ceramic or Nd:YAG ceramic or single crystals.
1 . A Fabry-Perot sensor assembly comprising:
an optical element defining a Fabry-Perot optical cavity therein, wherein the optical element comprises:
a first optical member comprising an endplate with an at least partially mirrored surface; and
a second optical member connected directly to the first optical member and axially adjacent to the first optical member with respect to a longitudinal axis of the Fabry-Perot sensor assembly; and
a sensor ferrule affixed to the second optical member, wherein the sensor ferrule defines a bore extending along the longitudinal axis to the second optical element;
wherein at least one of the first and second optical members is formed from a zirconate ceramic comprising at least one rare earth metal, or is formed from a hafnate ceramic comprising the at least one rare earth metal.
2 . The assembly as recited in claim 1 , wherein the at least one rare-earth metal comprises Lanthanum (La) and Gadolinium (Gd).
3 . The assembly as recited in claim 2 , wherein a mirrored ring is on the second optical member and faying with the Fabry-Perot optical cavity.
4 . The assembly as recited in claim 1 , wherein both the first and second optical members are formed from the hafnate ceramic.
5 . The assembly as recited in claim 1 , wherein both the first and second optical members are formed from the zirconate ceramic.
6 . The assembly as recited in claim 4 , wherein the second optical member is a main sensor body.
7 . The assembly as recited in claim 1 , wherein at least one of the first and second optical members is formed from La 0.8 Gd 1.2 Hf 2 O 7 ceramic.
8 . The assembly as recited in claim 1 , wherein at least one of the first and second optical members is formed from LaGdZr 2 O 7 ceramic.
9 . The assembly as recited in claim 2 , wherein the optical cavity is defined in the first optical member, wherein the first optical member includes a cavity rim extending axially from the endplate and surrounding the cavity peripherally, and wherein the second optical member is affixed to the cavity rim.
10 . The assembly as recited in claim 9 , wherein the second optical member includes a cavity rim surrounding the Fabry-Perot optical cavity peripherally, and wherein the first optical member is affixed to the cavity rim.
11 . The assembly as recited in claim 3 , further comprising anti-reflective coating on at least one surface of the optical element.
12 . The assembly as recited in claim 1 , wherein the first optical member is a diaphragm configured to deflect more than the third optical member under external pressure changes.
13 . A Fabry-Perot sensor assembly comprising:
an optical element defining a Fabry-Perot optical cavity therein, wherein the optical element comprises:
a first optical member comprising an endplate with an at least partially mirrored surface; and
a second optical member connected directly to the first optical member and axially adjacent to the first optical member with respect to a longitudinal axis of the Fabry-Perot sensor; and
a sensor ferrule affixed to the optical element, wherein the sensor ferrule is configured to physically connect to an optical fiber, optically aligning and spacing the optical fiber with the optical cavity, and wherein at least one of the first optical member and the second optical member is formed from a yttrium aluminum garnet (YAG) ceramic doped with a rare earth metal or is formed from a YAG single crystal doped with the rare earth metal.
14 . The assembly as recited in claim 13 , further comprising a cavity ring extending around the Fabry-Perot optical cavity and between the first optical member and the second optical member.
15 . The assembly of claim 14 , wherein the rare-earth metal is neodymium (Nd).
16 . The assembly of claim 15 , wherein both the first and second optical members are formed from the YAG ceramic.
17 . The assembly of claim 15 , wherein both the first and second optical members are formed from the YAG single crystal.
18 . The assembly of claim 1 , wherein the sensor ferrule is formed from the zirconium oxide ceramic comprising the at least one rare earth metal, or is formed from the hafnium oxide ceramic comprising the at least one rare earth metal.
19 . The assembly of claim 13 , wherein the sensor ferrule is formed from the YAG ceramic doped with the rare earth metal, or is formed from the YAG single crystal doped with the rare earth metal.