Optical fiber system to determine at least one physical parameter and method to determine at least one physical parameter using an optical fiber system
AssigneeKistler Holding AG
InventorsJack Waller, Filippo Rossi, Michael Summers, Kristopher Statham
Life of this patent
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Abstract
A sensor system includes an optical fiber, a modulable light source, and a photodetector. The optical fiber includes two sensing reflectors and a reference reflector. The optical fiber defines a distal end and a proximal end. A measuring segment is defined between the two sensing reflectors and disposed between the distal end and the proximal end. The light source is disposed at the proximal end and configured to emit light with a coherence length longer than the maximum distance between the sensing reflectors and the reference reflector.
Claims21
Sensor system, comprising:
- an optical fiber defining a proximal end and a distal end spaced apart from the proximal end;
- wherein the optical fiber includes a first sensing reflector and a second sensing reflector spaced apart from the first sensing reflector;
- wherein the optical fiber includes a reference reflector disposed between the proximal end and the distal end and spaced apart at least 1 millimeter from the distal end of the optical fiber;
- a modulable light source disposed at the proximal end of the optical fiber;
- a photodetector;
- and
- a measuring segment disposed between the distal end and the proximal end of the optical fiber and between the first sensing reflector and the second sensing reflector.
An optical sensing method employing an optical fiber, a modulable light source, and a photodetector, wherein the optical fiber defines a proximal end and a distal end spaced apart from the proximal end, wherein the optical fiber includes a first sensing reflector and a second sensing reflector spaced apart by a distance from the first sensing reflector to form a measuring segment of the optical fiber, wherein the first sensing reflector and the second sensing reflector are disposed between the proximal end and the distal end, wherein the optical fiber includes a reference reflector disposed between the proximal end and the distal end and spaced apart at least 1 millimeter from the distal end of the optical fiber, the method comprising the steps of:
- emitting from the light source into the proximal end of the fiber, light having a wavelength that is modulated over a bandwidth of the light as a function of time;
- forming a first modulated light signal resulting from interference between light reflected by the first sensing reflector with light reflected from the reference reflector;
- forming a second modulated light signal resulting from interference between light reflected by the second sensing reflector with light reflected from the reference reflector;
- comparing the first modulated light signal and the second modulated light signal to determine the distance between the first sensing reflector and the second sensing reflector;
- and
- wherein the bandwidth of the light that is being modulated and emitted into the proximal end of the optical fiber is narrower than the bandwidth of the reflectivity of each of the reference reflector and the first and second sensing reflectors.
Dependencies are inferred from the claim text.