Sensor system that uses embedded optical fibers

Patent metadata

Field	Value
Publication number	US-10161924-B2
Application number	US-201514599901-A
Country	US
Kind code	B2
Filing date	Jan 19, 2015
Priority date	Mar 24, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Sensor systems including an interferometer system are disclosed herein. In a general embodiment, the sensor system includes an optical fiber that is embedded into a sample, where the optical fiber has a reflective tip. The optical fiber is optically coupled to a sensor and a detector of the laser interferometer system. The sensor system further includes a computing device or circuit that is configured to receive electrical signals generated by the detector. The laser source is configured to emit light, which is coupled into the optical fiber. The light travels through the optical fiber until the light reaches the reflective tip, where it is reflected back through the optical fiber. The detector is impacted by the reflected light, and generates an electrical signal based upon the reflected light. The computing device generates a value that is indicative of a behavior of the sample based upon the electrical signal.

First claim

What is claimed is:

1. A sensor system in combination with a sample that is configured to measure a change in a property of reflected light that is indicative of a behavior of the sample, comprising:
a sample that is desirably analyzed; and
an optical fiber comprising:
an inner fiber through which light travels; and
a reflective surface applied to a cleaved tip of the optical fiber configured such that light travelling through the inner fiber is reflected back through the inner fiber by the reflective surface and does not impinge upon the sample, the reflective surface being orthogonal to the inner fiber at the cleaved tip, the cleaved tip of the optical fiber embedded in the sample that is desirably analyzed; and
a detector that is optically coupled to the optical fiber, the detector configured to generate an electrical signal responsive to receiving light reflected by the reflective surface, wherein the electrical signal is indicative of a behavior of the sample.

2. The sensor system of claim 1 , wherein the reflective surface is arranged in parallel to an exposed surface of the sample.

3. The sensor system of claim 2 , wherein the sample has a thickness defined by the exposed surface and a second surface, the thickness between 100 microns and one millimeter.

4. The sensor system of claim 3 , the sample being an explosive.

5. The sensor system of claim 4 , the explosive being silver acetylide-silver nitrate.

6. The sensor system of claim 1 , further comprising:
a laser interferometer that is optically coupled to the optical fiber, wherein the laser interferometer comprises a laser that is configured to emit light that travels through the inner fiber; and
a computing device that is electrically coupled to the detector, wherein the computing device is configured to receive the electrical signal and output the value that is indicative of the behavior of the sample based upon the electrical signal.

7. The sensor system of claim 6 , the behavior of the explosive being detonation velocity of the explosive, the value being an apparent particle velocity of the light.

8. The sensor system of claim 6 ; further comprising a second optical fiber positioned substantially parallel to the optical fiber the second optical fiber having a second inner fiber and a second reflective surface applied to a cleaved tip of the second optical fiber, the cleaved tip of the second optical fiber embedded in the sample, such that light travelling through the second inner fiber is reflected back through the second inner fiber by the second reflective surface.

9. The sensor system of claim 8 , the second reflective surface arranged in parallel with the exposed surface of the sample.

10. The sensor system of claim 9 , the reflective surface being embedded a first depth into the sample, the second reflective surface being embedded a second depth into the sample, the first and second depths being different from one another.

11. The sensor system of claim 1 , wherein the reflective surface comprises a plurality of layers, wherein the plurality of layers includes a layer of aluminum oxide, a layer of aluminum, and a layer of titanium.

12. The sensor system of claim 11 , wherein the layer of aluminum is between the layer of aluminum oxide and the layer of titanium, the layer of titanium being adjacent to the cleaved tip of the optical fiber.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Chavez Marcus Alexander
• Covert Timothy T
• Willis Michael David

Classifications

• G01N21/17

  Systems in which incident light is modified in accordance with the properties of the material investigated (where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63) · CPC title

• G01N2201/088

  Using a sensor fibre · CPC title

• G01D5/268

  using optical fibres (G01D5/28 - G01D5/38 take precedence) · CPC title

• G01N2201/06113

  Coherent sources; lasers · CPC title

• G01N33/227 Primary

  Explosives, e.g. combustive properties thereof · CPC title