Fiber optic fiber Fabry-Perot interferometer diaphragm sensor and method of measurement

A fiber Fabry-Perot interferometer diaphragm sensor for measuring pressure comprising:

• a diaphragm operable to deflect in response to a pressure acting on the diaphragm;
• a housing comprising a base and a stanchion, the stanchion disposed between the base and the diaphragm;
• an optic fiber disposed under tension between the base and the diaphragm;
• and
• a fiber Fabry-Perot interferometer element disposed within the optic fiber, the fiber Fabry-Perot interferometer element comprising a first internal mirror and a second internal mirror separated by a longitudinal length of the optic fiber, the longitudinal length of the optic fiber variable in response to any deflection of the diaphragm.

A fiber Fabry-Perot interferometer diaphragm sensor for measuring acceleration comprising:

• a proof mass coupled to a diaphragm, the diaphragm operable to deflect in response to an acceleration of the proof mass;
• a housing comprising a base and a stanchion, the stanchion disposed between the base and the diaphragm;
• an optic fiber disposed under tension between the base and the diaphragm;
• and
• a fiber Fabry-Perot interferometer element disposed within the optic fiber, the fiber Fabry-Perot interferometer element comprising a first internal mirror and a second internal mirror separated by a longitudinal length of the optic fiber, the longitudinal length of the optic fiber variable in response to any deflection of the diaphragm.

A fiber Fabry-Perot interferometer diaphragm sensor for measuring a magnetic field comprising:

• a magnetic body coupled to a diaphragm, the diaphragm operable to deflect in response to the magnetic field acting on the magnetic body;
• a housing comprising a base and a stanchion, the stanchion disposed between the base and the diaphragm;
• an optic fiber disposed under tension between the base and the diaphragm;
• and
• a fiber Fabry-Perot interferometer element disposed within the optic fiber, the fiber Fabry-Perot interferometer element comprising a first internal mirror and a second internal mirror separated by a longitudinal length of the optic fiber, the longitudinal length of the optic fiber variable in response to any deflection of the diaphragm.

A method of measurement comprising the steps of:

• providing a base;
• providing a diaphragm operable to deflect;
• coupling a fiber Fabry-Perot interferometer element under tension between the base and the diaphragm, the fiber Fabry-Perot interferometer element comprising a first internal mirror and a second internal mirror separated by a longitudinal length of optic fiber, the fiber Fabry-Perot interferometer element having a longitudinal strain that varies with the deflection of the diaphragm;
• and
• measuring the change in the longitudinal strain of the fiber Fabry-Perot interferometer element.