Single mode (SM) fiber optical reader system and method for interrogating resonant waveguide-grating sensor (S)

• US 20060180750A1
• Filed: 02/14/2005
• Published: 08/17/2006
• Est. Priority Date: 02/14/2005
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Gollier, Jacques, Piech, Garrett A.
• Granted Patent: US 7,346,233 B2
• Time in Patent Office: Days
• US Class Current: 250/227.110
• CPC Class Codes: G01N 21/7743 the reagent-coated grating coupling light in or out of the waveguide

Abstract

An optical reader system is described herein which has a single mode (SM) optical fiber launch/receive system that uses one or more SM optical fibers to interrogate a biosensor and does not use multimode (MM) optical fibers to interrogate the biosensor. The use of the SM optical fiber launch/receive system effectively reduces angular sensitivity, reduces unwanted system reflections, improves overall angular tolerance, and improves resonant peak reflectivity and resonant peak width. Two specific embodiments of the SM optical fiber launch/receive system are described herein which include: (1) a dual fiber collimator launch/receive system; and (2) a single fiber launch/receive system that interrogates the biosensor at a normal incidence.

Claims

1. An optical reader system, comprising:

a light source;

a light detector; and

a launch/receive system which uses at least one single mode (SM) optical fiber to interrogate a biosensor and does not use any multimode (MM) optical fibers to interrogate the biosensor.

2. The optical reader system of claim 1, wherein the use of the at least one SM optical fiber within said launch/receive system eliminates undesirable spatial modes which would be present if one or more MM optical fibers were used within said launch/receive system.

3. The optical reader system of claim 1, wherein the use of the at least one SM optical fiber within said launch/receive system causes said launch/receive system to have less sensitivity, in terms of wavelength variation, to angular deviations of the biosensor than if one or more MM optical fibers were used within said launch/receive system.

4. The optical reader system of claim 1, wherein the use of the at least one SM optical fiber within said launch/receive system causes a resonant wavelength associated with the biosensor to be more stable than if one or more MM optical fibers were used within said launch/receive system.

5. The optical reader system of claim 1, wherein said launch/receive system is a dual fiber collimator launch/receive system that includes a lens located a predetermined distance away from the biosensor which enables the rejection of Fresnel reflections and parasitic reflections which are created during the interrogation of the biosensor.

6. The optical reader system of claim 1, wherein said launch/receive system is a dual fiber collimator launch/receive system which includes a lens located a predetermined distance away from the biosensor that effectively creates an input grating and an output grating out of a single grating within the biosensor during the interrogation of the biosensor.

7. The optical reader system of claim 1, wherein said launch/receive system is a single fiber launch/receive system that interrogates the biosensor at a normal incidence.

8. The optical reader system of claim 7, wherein said single fiber launch/receive system includes a circular polarizer which rejects Fresnel reflections and parasitic reflections that are created during the interrogation of the biosensor.

9. The optical reader system of claim 7, wherein said single fiber launch/receive system by interrogating the biosensor at normal incidence effectively minimizes its sensitivity to angular deviations of the biosensor in terms of power fluctuations and minimizes a resonant peak width while simultaneously maximizing an angular tolerance and maximizing a resonance reflection efficiency.

10. The optical reader system of claim 1, wherein said biosensor is a resonant waveguide grating (RWG) sensor.

11. A method for interrogating a biosensor, said method comprising the step of:

using a launch/receive system which uses at least one single mode (SM) optical fiber incorporated therein to interrogate a biosensor and does not use any multimode (MM) optical fibers to interrogate the biosensor.

12. The method of claim 11, wherein the use of the at least one SM optical fiber within said launch/receive system eliminates undesirable spatial modes which would be present if one or more MM optical fibers were used within said launch/receive system.

13. The method of claim 11, wherein the use of the at least one SM optical fiber within said launch/receive system causes said launch/receive system to have less sensitivity, in terms of wavelength variation, to angular deviations of the biosensor than if one or more MM optical fibers were used within said launch/receive system.

14. The method of claim 11, wherein the use of the at least one SM optical fiber within said launch/receive system causes a resonant wavelength associated with the biosensor to be more stable than if one or more MM optical fibers were used within said launch/receive system.

15. The method of claim 11, wherein said launch/receive system is a dual fiber collimator launch/receive system that includes a lens located a predetermined distance away from the biosensor which enables the rejection of Fresnel reflections and parasitic reflections which are created during the interrogation of the biosensor.

16. The method of claim 11, wherein said launch/receive system is a dual fiber collimator launch/receive system which includes a lens located a predetermined distance away from the biosensor that effectively creates an input grating and an output grating out of a single grating within the biosensor during the interrogation of the biosensor.

17. The method of claim 11, wherein said launch/receive system is a single fiber launch/receive system that interrogates the biosensor at a normal incidence.

18. The method of claim 17, wherein said single fiber launch/receive system includes a circular polarizer which rejects Fresnel reflections and parasitic reflections that are created during the interrogation of the biosensor.

19. The method of claim 11, wherein said single fiber launch/receive system by interrogating the biosensor at normal incidence effectively minimizes its sensitivity to angular deviations of the biosensor and minimizes a resonant peak width while simultaneously maximizing an angular tolerance and maximizing a resonance reflection efficiency.

20. The method of claim 11, wherein said biosensor is a resonant waveguide grating (RWG) sensor.

21. An interrogation system, comprising:

a light source;

a light detector; and

a dual fiber collimator launch/receive system which uses a first single mode (SM) fiber optical fiber to output a sensor input beam to a biosensor; and

said dual fiber collimator launch/receive system uses a second single mode (SM) fiber to receive a sensor output beam from the biosensor.

22. The interrogation system of claim 21, wherein said dual fiber collimator launch/receive system includes a lens located a predetermined distance away from the biosensor which enables the rejection of Fresnel reflections and parasitic reflections which are created while interrogating the biosensor.

23. The interrogation system of claim 21, wherein said dual fiber collimator launch/receive system includes a lens located a predetermined distance away from the biosensor that effectively creates an input grating and an output grating out of a single grating within the biosensor while interrogating the biosensor.

24. The interrogation system of claim 21, wherein said dual fiber collimator launch/receive system includes a lens located an adjustable distance away from the biosensor which enables one to measure the loss coefficient alpha α

of the biosensor.

25. The interrogation system of claim 21, wherein said biosensor is a resonant waveguide grating (RWG) sensor.

26. An interrogation system comprising:

a light source;

a light detector; and

a single fiber launch/receive system which uses a single mode (SM) fiber optical fiber to output a sensor input beam at a normal incidence to a biosensor; and

said single fiber launch/receive system also uses the SM fiber to receive a sensor output beam at the normal incidence from the biosensor.

27. The interrogation system of claim 26, wherein said single fiber launch/receive system includes a circular polarizer which rejects Fresnel reflections and parasitic reflections that are created while interrogating the biosensor.

28. The interrogation system of claim 26, wherein said single fiber launch/receive system by interrogating the biosensor at normal incidence effectively minimizes its sensitivity to angular deviations of the biosensor and minimizes a resonant peak width while simultaneously maximizing an angular tolerance and maximizing a resonance reflection efficiency.

29. The interrogation system of claim 26, wherein said biosensor is a resonant waveguide grating (RWG) sensor.