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US 2026/0036472 A1Published application
Optical sensing method and optical sensor system for an optical sensing method
AssigneeKistler Holding AG
InventorJack Waller
Life of this patent
Estimating the term…
Abstract
An optical sensor system is adapted for a sensing method using fiber segment interferometry. A sensing element with a thermo-optic coefficient larger than the thermo-optic coefficient of an optical fiber is arranged at a distal end of the fiber.
Claims19
An optical sensing method, the method comprising the steps of:
- providing a first optical fiber segment that includes a first optical fiber that defines a proximal end and a distal end disposed spaced apart from the proximal end, wherein the first optical fiber has a thermo-optic coefficient and a reference reflector disposed within the first optical fiber between the proximal end of the first optical fiber and the distal end of the first optical fiber;
- disposing at the distal end of the first optical fiber, a sensing element having a thermo-optic coefficient that is larger in magnitude than the thermo-optic coefficient of the first optical fiber and including a first reflective surface disposed parallel to and spaced apart from a second reflective surface;
- emitting light from a light source into the proximal end of the first optical fiber segment and propagating the light from the proximal end of the first optical fiber segment towards the distal end of the first optical fiber segment, wherein the light is characterized by a center wavelength and a linewidth;
- modulating the center wavelength of the light emitted from the light source over a modulation range as a function of time, wherein the modulation range has a bandwidth that is larger in magnitude than the linewidth of the light emitted from the light source;
- wherein a first reflected portion of the light emitted from the light source is reflected from the reference reflector;
- wherein a second reflected portion of the light emitted from the light source is reflected from the sensing element;
- using a photodetector to detect the first reflected portion of the light from the reference reflector and the second reflected portion of the light from the sensing element;
- using an analyzer connected to the photodetector to analyze the first reflected portion of the light from the reference reflector and the second reflected portion of the light from the sensing element;
- and
- establishing a temperature of the sensing element based on the influence of the thermo-optic coefficient of the sensing element on the light detected by the photodetector.
7 more elements
An optical sensor system comprising:
- a light source configured to emit light characterized by a center wavelength and a linewidth, wherein the light source is configured to modulate over a modulation range as a function of time, the wavelength of the center wavelength of the light emitted by the light source, and wherein the bandwidth of the modulation range is larger than the linewidth of the light emitted by the light source;
- a first optical fiber segment defining a proximal end and a distal end disposed axially spaced apart from the proximal end, wherein the first optical fiber segment includes a first optical fiber disposed between the proximal end of the first optical fiber segment and the distal end of the first optical fiber segment and configured to allow light to propagate from the proximal end of the first optical fiber segment towards the distal end of the first optical fiber segment;
- a first reference reflector disposed within the first optical fiber between the proximal end and the distal end of the first optical fiber;
- a sensing element disposed facing the distal end of the first optical fiber, and having a thermo-optic coefficient larger than the thermo-optic coefficient of the first optical fiber, a first partially reflective surface and a second reflective surface that is disposed spaced apart from and parallel to the first reflective surface and either partially reflective or completely reflective;
- a detector configured and to detect as a function of time, a first interference pattern between light partially reflected by the reference reflector and partially reflected by the first reflective surface of the sensing element;
- wherein the detector is configured and disposed to detect as a function of time, a second interference pattern between light partially reflected by the reference reflector and partially reflected by the second reflective surface of the sensing element;
- an analyzer connected to the detector, wherein the analyzer is configured to analyze the first interference pattern and the second interference pattern to determine a first optical distance between the reference reflector and the first reflective surface of the sensing element;
- and
- wherein the analyzer is configured to determine a second optical distance between the reference reflector and the second reflecting surface of the sensing element.
6 more elements
Dependencies are inferred from the claim text.