CPC G01L 11/02 (2013.01) [G01C 19/727 (2013.01); G01N 21/45 (2013.01); G02B 27/10 (2013.01)] | 26 Claims |
1. A pressure sensor for determining pressure in an environment, comprising:
a first source for emitting a coherent reference light characterized by a reference light frequency;
a first optical circulator in optical communication with the first source via an optical fiber;
a second source for emitting a measurement coherent light characterized by a measurement light frequency;
a second optical circulator in optical communication with the second source via an optical fiber;
a fiber optic coupler in optical communication with the first optical circulator via an optical fiber and with the second optical circulator via an optical fiber;
a reference cavity in optical communication with the fiber optic coupler via an optical fiber and configured to receive at least a portion of the coherent reference light from the fiber optic coupler; wherein the reference cavity is characterized by a reference resonance frequency; and wherein a pressure in a reference space of the reference cavity is less than or equal to 0.1 mTorr;
a measurement cavity in optical communication with the fiber optic coupler via an optical fiber and configured to receive at least a portion of the measurement coherent light from the fiber optic coupler; wherein the measurement cavity is characterized by a measurement resonance frequency;
a measurement lock-in mechanism in optical communication with the first optical circulator via an optical fiber and configured to send an electrical signal at least to the second source based on at least the measurement resonance frequency; and
a reference lock-in mechanism in optical communication with the second optical circulator via an optical fiber and configured to send an electrical signal at least to the first source based on at least the reference resonance frequency;
wherein a pressure of the environment is determined based on the reference resonance frequency and the measurement resonance frequency.
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