Optical sensor arrangement

• US 6,343,168 B1
• Filed: 12/31/1999
• Issued: 01/29/2002
• Est. Priority Date: 10/02/1997
• Status: Expired due to Fees

• Current Assignee: Luna Innovations, Inc.
• Original Assignee: Luna Innovations, Inc.
• Inventors: Jones, Mark E., Murphy, Kent A.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): ASSAF, FAYEZ G
• Application Number:
  US09/476,656
• Time in Patent Office: 760 Days
• Field of Search: 385/37, 385/24, 385/12, 250/227.14, 250/227.18, 250/227.23
• US Class Current: 385/37
• CPC Class Codes: G01D 5/35345 using Amplitude variations to detect the measured quantity
• CPC Class Codes: G01D 5/35377 Means for amplifying or modifying the measured quantity
• CPC Class Codes: G02B 6/02095 Long period gratings, i.e. transmission gratings coupling light between core and cladding modes
• CPC Class Codes: G02B 6/02104 characterised by the coating external to the cladding, e.g. coating influences grating properties
• CPC Class Codes: G02B 6/14 Mode converters

Abstract

An optical sensor arrangement is provided. The arrangement comprises a light source coupled to an optical waveguide. The optical waveguide has at least one long period grating that promotes an excitation of confined propagating light into higher order modes causing an excitation of a sensing mechanism. A detector is coupled to the optical waveguide to detect a resulting optical signal.

Claims

1. An optical sensor arrangement comprising:

a light source;

an optical waveguide coupled to the light source;

at least one long period grating disposed within the optical waveguide, wherein the long period grating has a plurality of index perturbations spaced apart by a periodic distance Λ

, wherein the long period grating promotes an excitation of confined propagating light into higher order modes causing an excitation of a sensing mechanism;

wherein the sensing mechanism receives light coupled from the long period grating; and

a detector coupled to the optical waveguide wherein the detector detects a resulting optical signal.

2. An optical sensor arrangement according to claim 1, wherein the periodic distance is irregular.

3. An optical sensor arrangement according to claim 2, wherein the periodic distance is 10 μ

m≦

Λ

≦

1500 μ

m.

4. An optical sensor arrangement according to claim 1, wherein the periodic distance is 10 μ

m≦

Λ

≦

1500 μ

m.

5. An optical sensor arrangement according to claim 1, wherein the sensing mechanism is selected from the group consisting of:

an absorption mechanism;

a polarization mechanism;

a phase changing mechanism;

an electromagnetic property changing mechanism; and

a fluorescent signal.

6. An optical sensor arrangement according to claim 1, wherein the optical waveguide is selected from the group consisting of:

a planar optical waveguide;

an integrated optic waveguide; and

a fiber optic waveguide.

7. An optical sensor arrangement according to claim 6, wherein the optical waveguide is a fiber optic waveguide.