Method and Optical Shield for Detecting Tampering

• US 20150226637A1
• Filed: 02/12/2014
• Published: 08/13/2015
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: OpticalLock, Inc.
• Original Assignee: OpticalLock, Inc.
• Inventors: Sanchez, Jorge, Fuller, Carol E.
• Granted Patent: US 9,329,098 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01M 11/088 of optical fibres; Mechanical features associated with the optical testing of optical fibres
• CPC Class Codes: G01M 11/30 Testing of optical devices, constituted by fibre optics or optical waveguides
• CPC Class Codes: G01M 11/31 with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
• CPC Class Codes: G08B 13/186 using light guides, e.g. optical fibres

Abstract

A method includes conforming an arrangement of an optical fiber to an object to detect tampering with the object when the optical fiber arrangement is changed, measuring an optical signature of the optical fiber arrangement in a first measurement, measuring the optical signature of the optical fiber arrangement at a time after the first measurement in a second measurement, and comparing the first and second measurements to detect tampering with the object from a change in the optical fiber arrangement. In another embodiment, an optical shield includes an optical fiber arranged to detect tampering with an object resulting from a change in the optical fiber arrangement and an optical fiber carrier coupled to the optical fiber for conforming the optical fiber arrangement to the object.

Claims

1. A method comprising:

conforming an arrangement of an optical fiber to an object to detect tampering with the object when the time and frequency domains of said optical fiber are changed;

wherein said tampering is detected by measuring an optical signature of the optical fiber arrangement with a first light pulse, in a first measurement wherein said optical signature is characterized by the unique optical response of the optical fiber wherein said first measurement comprises measuring the time and frequency domains associated with said optical fiber;

measuring the optical signature of the optical fiber arrangement at a time after the first measurement with a second light pulse, in a second measurement;

wherein said second measurement comprises measuring the time and frequency domains associated with said optical fiber and

comparing the first and second measurements to detect tampering with the object from a change in the time and frequency domains of said optical fiber.

2. The method of claim 1 further comprising generating at least one of the first and second measurements by measuring said time and frequency domains of light transmitted from a light source and propagated through the optical fiber wherein said optical response is measured by an optical signature measuring device wherein said optical signature measuring device measures at least one of the following, bending loss, fracture reflections or chromatic, modal, polarization or four-wave mixing mode dispersions.

3. The method of claim 2 further comprising generating at least one of the first and second measurements by measuring said time and frequency domains of the transmitted light wherein said optical signal measuring device is an optical spectrum analyzer configured with wavelength selective means.

4. The method of claim 2 further comprising transmitting light from a light source comprising one of a light emitting diode (LED), a semiconductor laser, and a vertical-cavity surface-emitting laser (VCSEL).

5. The method of claim 2 further comprising recording at least one of the first and second measurements of the optical signature on at least one of an RFID tag, a computer readable medium, and a computer.

6. The method of claim 2 further comprising measuring the optical signature to include an optical response of the optical fiber to at least one of bending, fracturing, chromatic dispersion, modal dispersion, polarization mode dispersion, and four-wave mixing mode dispersion or a combination thereof.

7. The method of claim 2 further comprising generating a tampering indicator from the first and second measurements.

8. The method of claim 7 further comprising generating the tampering indicator as one of a true/false signal and a level of confidence variable.

9. The method of claim 7 further comprising generating the tampering indicator to discriminate against false alarms.

10. The method of claim 9 further comprising generating the tampering indicator by comparing a difference between the first and second measurements to a threshold.

11. The method of claim 9 further comprising generating the tampering indicator by comparing a difference between the first and second measurements to a threshold allowing for measurement error and environmental effects including at least one of temperature, humidity, barometric pressure, and vibration.

12. The method of claim 2 further comprising recording the first measurement on a secure server over the Internet and retrieving the first measurement over the Internet from the secure server.

13. An optical shield comprising:

an optical fiber arranged to detect tampering with an object resulting from a change in the time and frequency domain signature of said optical fiber; and

an optical fiber carrier coupled to the optical fiber for conforming the optical fiber arrangement to the object, said optical shield further comprising a tampering indicator, a beam splitter, a computer readable storage medium, an optical signature measuring device configured with a wavelength selective means wherein, said optical signature measuring device comprises a means for measuring the optical signature of said optical fiber in response to a first and second light pulse wherein said optical signature is characterized by the unique bending loss, fracture reflections or chromatic, modal, polarization mode or four-wave mixing mode dispersions created by said optical fiber in response to said first and said second light pulse, wherein said computer readable medium comprises a means of storing said optical signature, wherein said computer readable medium comprises a means of analyzing said change by comparing a difference in the optical signature of said optical fiber created between a first and second measurement of said time and frequency domains in response to said first and second light pulse, said tampering indicator comprising a means to create an alarm when a change in optical signature is detected.

14. The optical shield of claim 13 further comprising an optical coupler terminating at least one end of the optical fiber for connecting the optical fiber to at least one of a light source, a collimator, a bi-directional coupler, aid beam splitter, and said optical signature measuring device.

15. The optical shield of claim 13, wherein said optical fiber comprises one of a single-mode optical fiber and a multi-mode optical fiber.

16. The optical shield of claim 13, wherein said optical fiber carrier further comprises at least one of tape, bubble wrap, sheet wrap, shrink wrap, expanding foam, an adhesive, plastic air bags, pellets, paper, and cardboard.

17. The optical shield of claim 13, wherein said optical fiber arrangement comprises at least one of a bend, a curve, a series of curves, a spiral, and a fracture.

18. The optical shield of claim 13, wherein said object comprises one of a regular slotted container, an intermodal freight container, a semi trailer, a building, a vault, a document, and a container closed by a container cap.