Integrated optical compensating refractometer apparatus

• US 5,377,008 A
• Filed: 04/02/1992
• Issued: 12/27/1994
• Est. Priority Date: 09/20/1990
• Status: Expired due to Fees

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Ridgway, Richard W., Wood, Van E., Busch, James R., Boiarski, Anthony A.
• Primary Examiner(s): Turner, Samuel A.
• Application Number:
  US07/862,494
• Time in Patent Office: 999 Days
• Field of Search: 356/345, 356/361, 356/128, 356/133, 385/12, 385/14, 385/13, 250/227.14, 250/227.19, 250/227.24, 250/227.25, 250/227.27, 250/227.28
• US Class Current: 356/481
• CPC Class Codes: G01J 2009/023 of the integrated optical type
• CPC Class Codes: G01N 2021/1751 Constructive features therefore, e.g. using two measurement cells
• CPC Class Codes: G01N 21/45 using interferometric methods; using Schlieren methods
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 2201/0245 with insertable-removable part
• CPC Class Codes: G01N 2201/0873 Using optically integrated constructions
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G02B 2006/12097 Ridge, rib or the like
• CPC Class Codes: G02B 2006/12138 Sensor
• CPC Class Codes: G02B 2006/12159 Interferometer
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths

Abstract

An apparatus useful in immunoassay of a fluid, light is directed to an optical sensor wherein the light is transmitted to a replaceable optical device that is responsive to index of refraction in a sensing region thereof that is exposed to the fluid. One portion of the light is transmitted via a compensation path that includes the sensing region to a first detector. Another portion of the light is transmitted via a sensing path that includes the sensing region to another detector. In one embodiment a ratioing device receives an output from each detector and provides a signal responsive to the ratio of the outputs. The replaceable optical device typically comprises a pair of channel waveguides in directional coupling arrangement, or a pair of channel waveguides in an interferometer arrangement, or a ridge waveguide having a curved or serpentine path configured so that nonspecific sensing effects are compensated.

Claims

1. Apparatus useful in determining the properties of a fluid, comprising:

means for directing light to an input portion of optical sensing means having

means for transmitting the light to replaceable optical means, the replaceable optical means responsive to index of refraction in a predetermined sensing region thereof that is exposed to the fluid, wherein the replaceable optical means comprises a plurality of channel waveguide means in directional coupling arrangement,

means for transmitting a first predetermined portion of the light via a compensating path that includes the predetermined sensing region to first detecting means, wherein the channel waveguide means in the sensing region comprises a compensating superstrate that can react with the fluid,

means for transmitting a second predetermined portion of the light via a sensing path that includes the predetermined sensing region to second detecting means, wherein the channel waveguide means in direct coupling arrangement in the sensing region comprises a sensing superstrate that can react with the fluid, and

means for receiving an output from each detecting means and providing a signal responsive to the ration of the outputs;

wherein nonspecific effects are compensated.

2. Apparatus as in claim 1, wherein the sensing superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen, and the compensating superstrate comprises inactivated antigen or antibody having an index of refraction that changes in response to nonspecific effects.

3. Apparatus as in claim 1, wherein waveguide in the channel waveguide means comprises raised waveguide.

4. Apparatus useful in determining the properties of a fluid, comprising:

means for directing light to an input portion of optical sensing means having

means for transmitting the light to replaceable optical means, the replaceable optical means responsive to index of refraction in a predetermined sensing region thereof that is exposed to the fluid,

means for transmitting a first predetermined portion of the light via a compensating path that includes the predetermined sensing region to first detecting means,

means for transmitting a second predetermined portion of the light via a sensing path that includes the predetermined sensing region to second detecting means, and

means for receiving an output from each detecting means and providing a signal responsive to the ration of the outputs, wherein the replaceable optical means comprises ridge waveguide means having first and second serpentine paths that form the compensating and the sensing paths respectively, wherein the first path comprises a superstrate that can react with the fluid for compensating for nonspecific effects of the fluid, and wherein the second path comprises a superstrate that can react with the fluid for measuring properties thereof.

5. Apparatus as in claim 4, wherein the sensing superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen, and the compensating superstrate comprises inactivated antigen or antibody having an index of refraction that changes in response to nonspecific effects.

6. Apparatus useful in determining the properties of a fluid, comprising:

means for directing light to an input portion of optical sensing means having

means for transmitting the light to replaceable optical means, the replaceable optical means responsive to index of refraction in a predetermined sensing region thereof that is exposed to the fluid,

means for transmitting a first predetermined portion of the light via a compensating path that includes the predetermined sensing region to first detecting means,

means for transmitting a second predetermined portion of the light via a sensing path that includes the predetermined sensing region to second detecting means, and

means for receiving an output from each detecting means and providing a signal responsive to the ration of the outputs, wherein the replaceable optical means comprises U-bend waveguide means having first and second paths that form the compensating and the sensing paths respectively, wherein the first path comprises a superstrate that can react with the fluid for compensating for nonspecific effects of the fluid, and wherein the second path comprises a superstrate that can react with the fluid for measuring properties thereof.

7. Apparatus as in claim 6, wherein the sensing superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen, and the compensating superstrate comprises inactivated antigen or antibody having an index of refraction that changes in response to nonspecific effects.

8. Apparatus useful in determining the properties of a fluid, comprising:

means for directing light to an input portion of optical sensing means having

means for transmitting the light to replaceable optical means, the replaceable optical means responsive to index of refraction in a predetermined sensing region thereof that is exposed to the fluid,

means for transmitting a first predetermined portion of the light via a compensating path that includes the predetermined sensing region to first detecting means,

means for transmitting a second predetermined portion of the light via a sensing path that includes the predetermined sensing region to second detecting means, and

means for receiving an output from each detecting means and providing a signal responsive to the ratio of the outputs;

wherein the replaceable optical means comprises S-bend waveguide means having first and second paths that form the compensating and the sensing paths respectively, wherein the first path comprises a superstrate that can react with the fluid for compensating for nonspecific effects of the fluid, and wherein the second path comprises a superstrate that can react with the fluid for measuring properties thereof.

9. Apparatus as in claim 8, wherein the sensing superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen, and the compensating superstrate comprises inactivated antigen or antibody having an index of refraction that changes in response to nonspecific effects.

10. Apparatus useful in immunoassay of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a first optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

a second optical waveguide with an end for receiving or exiting light,

the first and second optical waveguides having portions which are positioned close together over an interaction length L, so that light in the first waveguide evanescently couples into the second waveguide or vice versa, and

a first superstrate of known and constant index of refraction covering the first optical waveguide except for the interaction length L, and covering the second waveguide except for the interaction length L;

wherein the interactive length L of the first waveguide is covered by a second superstrate that can react with the fluid, and the interactive length L of the second waveguide is covered by a third superstrate that can react with the fluid.

11. Apparatus as in claim 10, wherein the second superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen and the third superstrate comprises inactivated antigen or antibody.

12. Apparatus as in claim 10, wherein the second optical waveguide comprises a second end for receiving and exiting light.

13. Apparatus as in claim 10, wherein the first and second waveguides comprise raised waveguides.

14. Apparatus useful in determining the properties of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a first optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

a second optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the first and second optical waveguides having portions which are positioned close together over an interaction length L, so that light in the first waveguide couples into the second waveguide or vice versa,

a channel between the waveguides in an interaction length L, wherein the coupling between the waveguides is enhanced,

a first superstrate of known and constant index of refraction covering the first and second optical waveguide except for the channel in interaction length L.

15. Apparatus as in claim 14, wherein a channel is etched into the substrate between the first and second waveguides.

16. Apparatus as in claim 14, comprising a channel between the first and second waveguides, the waveguides being raised at least partially above the surface of the substrate.

17. Apparatus as in claim 14, comprising a Y-directional coupler for providing light to the first and second light receiving waveguide ends.

18. Apparatus as in claim 14, wherein the second optical waveguide comprises only a first end for receiving and exiting light.

19. Apparatus as in claim 14, wherein the channel is covered by alternating strips of a second superstrate and a third superstrate that can react with the fluid.

20. Apparatus as in claim 19, wherein the second superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen, and the third superstrate comprises inactivated antigen or antibody having an index of refraction that changes in response to nonspecific effects.

21. Apparatus as in claim 14, wherein the first and second waveguides comprise raised waveguides.

22. Apparatus useful in determining the properties of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a first optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

a second optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the first and second optical waveguides having portions which are positioned close together over an interaction length L1, so that light in the first waveguide couples into the second waveguide or vice versa,

a third optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the third and second optical waveguides having portions which are positioned close together over an interaction length L2, so that light in the third waveguide couples into the second waveguide or vice versa,

a first channel between the first and second waveguides in an interaction length L1, wherein the coupling between the waveguides above the substrate is enhanced, and

a second channel between the third and second waveguides in an interaction length L2, wherein the coupling between the waveguides above the substrate is enhanced, and

a first superstrate of known and constant index of refraction covering the first, second, and third optical waveguides except for first and second channels in interaction lengths L1 and L2.

23. Apparatus as in claim 22, wherein the uncovered portions of the first channel are covered by a second superstrate that can react with the fluid, and wherein uncovered portions of the second channel are covered by a third superstrate that can react with the fluid.

24. Apparatus as in claim 23, wherein the third superstrate is capable of providing predominantly nonspecific binding reactions.

25. Apparatus useful in determining the properties of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a first optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

a second optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the first and second optical waveguides having portions which are positioned close together over an interaction length L1, so that light in the first waveguide couples into the second waveguide or vice versa,

a third optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the third and second optical waveguides having portions which are positioned close together over an interaction length L2, so that light in the third waveguide couples into the second waveguide or vice versa,

a first channel between the first and second waveguides in an interaction length L1, wherein the coupling between the waveguides above the substrate is enhanced,

a second channel between the third and second waveguides in an interaction length L2, wherein the coupling between the waveguides above the substrate is enhanced, and

a first superstrate of known and constant index of refraction covering the first, second, and third optical waveguides except for the first and third waveguide portions within the interaction lengths L1 and L2.

26. Apparatus as in claims 25, wherein the uncovered portions of the first waveguide are covered by a second superstrate that can react with the fluid, and wherein uncovered portions of the third waveguide are covered by a third superstrate that can react with the fluid.

27. Apparatus useful in determining the properties of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a first optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

a second optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light.

the first and second optical waveguides having portions which are positioned close together over an interaction length L1, so that light in the first waveguide couples into the second waveguide or vice versa,

a third optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the third and second optical waveguides having portions which are positioned close together over an interaction length L2, so that light in the third waveguide couples into the second waveguide or vice versa,

a first channel between the first and second waveguides in an interaction length L1, wherein the coupling between the waveguides above the substrate is enhanced,

a second channel between the third and second waveguides in an interaction length L2, wherein the coupling between the waveguides above the substrate is enhanced, and

a first superstrate of known and constant index of refraction covering the first, second, and third optical waveguides except for the first and third waveguide portions, and the first and second channels within the interaction length L1 and L2.

28. Apparatus as in claim 27, wherein the uncovered portions of the first waveguide and first channel are covered by a second superstrate that can react with the fluid, and wherein uncovered portions of the third waveguide and second channel are covered by a third superstrate that can react with the fluid.

29. Apparatus useful in determining the properties of a fluid, comprising:

a substrate with an optical directional coupler integrated therein having,

a Y-split coupler having a first optical waveguide with an end for receiving light and second and third optical waveguides with ends for exiting light,

a fourth optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the second and fourth optical waveguides having portions which are positioned close together over an interaction length L1, so that light in the second waveguide couples into the fourth waveguide or vice versa,

a fifth optical waveguide with a first end for receiving or exiting light and a second end for receiving or exiting light,

the third and fifth optical waveguides having portions which are positioned close together over an interaction length L2, so that light in the fifth waveguide couples into the third waveguide or vice versa,

a first channel between the second and fourth waveguides in the interaction length L1,

a second channel between the third and fifth waveguides in the interaction length L2, and

a first superstrate of known and constant index of refraction covering the second, third, fourth and fifth optical waveguides except for the first channel and second channel within the interaction lengths L1 and L2.

30. Apparatus as in claim 29, wherein the waveguides comprise raised waveguides.

31. Apparatus as in claim 29, wherein the first channel in the interactive length L1 covered by a second superstrate that can react with the fluid, and the second channel in the interactive length L2 is covered by a third superstrate that can react with the fluid.

32. Apparatus as in claim 29, wherein the second superstrate comprises antigen or antibody, having an index of refraction that changes in response to a binding reaction of antibody or antigen and the third superstrate comprises inactivated antigen or antibody.

33. Apparatus as in claim 29, wherein the fourth optical waveguide comprises only a first end for receiving and exiting light, and the fifth optical waveguide comprises only a first end for receiving and exiting light.