Integrated sensor

• US 20020031838A1
• Filed: 07/27/2001
• Published: 03/14/2002
• Est. Priority Date: 07/28/2000
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Coldren, Larry A., Meinhart, Carl D., Stultz, Timothy J.
• Granted Patent: US 6,899,849 B2
• Time in Patent Office: Days
• US Class Current: 436/514
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 2021/7776 Index
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/39 using tunable lasers
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• 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: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

An integrated optical chip device for molecular diagnostics comprising a tunable laser cavity sensor chip using heterodyned detection at the juncture of a sensor laser and a reference laser, and including a microfluid chip to which the sensor chip is flip-chip bonded to form a sample chamber that includes exposed evanescent field material of the tunable laser cavity to which fluid to be diagnosed is directed.

Claims

1. An integrated optical chip device for molecular diagnostics, comprising:

(a) a pair of lasers comprising a reference laser and a sensor laser, each comprising a waveguide having a gain section, opposing mirrors, including a partially transmissive mirror and a coherent light beam output section, at least one of the waveguides having a phase control section, the coherent light beam output sections being joined to enable coherent light outputs of the reference and sensor lasers to interfere;

(b) a sample chamber at least partly formed through and exposing evanescent field material of the sensor laser, having an inlet for receiving a fluid and an outlet for discharging effluent; and

(c) a heterodyne detector at the juncture of the reference and sensor coherent light output sections, for detecting a change in the frequency of the coherent light output from the sensor laser resulting from a change in the index of refraction of fluid in the sample chamber.

2. The chip device of claim 1 in which an adsorbent for molecules to be diagnosed is provided on the exposed material of the sensor laser.

3. The chip device of claim 2 in which the sample chamber comprises at least one dielectrophoretic electrode to increase the concentration of molecules to be diagnosed adjacent said adsorbent.

4. The chip device of claim 1 in which said inlet and outlet are formed by microchannels through the body of said chip.

5. The chip device of claim 1 in which said sample chamber is between the control section and sampled grating mirror section of the sensor laser.

6. The chip device of claim 1 in which the sensor laser includes said phase control section.

7. The chip device of claim 1 wherein the mirror on each laser opposing the partially transmissive mirror is a facet mirror.

8. The chip device of claim 1 wherein the partially transmissive mirror and the opposing mirror are both sampled-grating mirrors having different sampling periods.

9. The chip device of claim 1 in which said exposed evanescent field region is between the gain section and one of the mirrors of the sensor laser.

16. A system for the identification of a molecular species in a fluid comprising a plurality of pairs of reference and sensor lasers of claim 2 having a common source of fluid to be diagnosed.

20. A method for detecting a molecular species in a fluid, comprising:

directing fluid to be tested for said molecular species to the inlet of a sample chamber of an integrated optical chip device of claim 1;

and

detecting a shift in frequency of the heterodyned coherent light outputs of the reference and sensor lasers thereof.

10. An integrated optical chip device for molecular diagnostics, comprising:

(a) a tunable laser cavity sensor chip having;

(i) a reference laser and a sensor laser, each comprising a waveguide having a gain section, opposing mirrors, including a partially transmissive mirror, and a coherent light beam output section, at least one of the waveguides having a phase control section, the coherent light beam output sections being joined to enable coherent light outputs of the reference and sensor lasers to interfere;

(ii) a sensor cavity formed through and exposing evanescent field material of the sensor laser for receiving a fluid to be diagnosed; and

(iii) a heterodyne detector at the juncture of the reference and sensor coherent light output sections for detecting a change in the frequency of the coherent light output from the sensor laser resulting from a change in the index of refraction of fluid in the sensor cavity; and

(b) a microfluidic chip formed with a sample cavity having an inlet for receiving fluid and an outlet for discharging effluent;

said tunable laser cavity sensor chip being connected to said mircrofluidic chip whereby the sensor and sample cavities define a sample chamber.

11. The chip device of claim 10 in which the tunable laser cavity sensor chip and the microfluidic chip are connected by flip-chip bonding.

12. The chip device of claim 10 in which adsorbent material for molecules to be diagnosed is provided on the exposed material of the sensor laser.

13. The chip device of claim 12 in which the sample cavity comprises at least one dielectrophoetic electrode to increase the concentration of molecules to be diagnosed adjacent said adsorbent.

14. The chip device of claim 10 in which said sensor cavity is between the control section and sampled grating mirror section of the sensor laser.

15. The chip device of claim 10 in which the sensor laser includes said phase control section.

17. The system of claim 16 in which the outlet of one pair of reference and sensor lasers is connected in series to the outlet of another pair of reference and sensor lasers.

18. A system for the identification of a molecular species in a fluid comprising a plurality of integrated optical chip devices of claim 12 having a common source of fluid to be diagnosed.

19. The system of claim 18 in which the outlet of one integrated optical chip device is connected in series to the inlet of another integrated optical chip device.

21. A method for detecting a molecular species in a fluid, comprising:

directing fluid to be tested for said molecular species to the inlet of a sample chamber of an integrated optical chip device of claim 10; and

detecting a shift in frequency of the heterodyned coherent light outputs of the reference and sensor lasers thereof.

22. A method for detecting a plurality of molecular species in a fluid, comprising:

establishing a heterodyned frequency of a first pair of lasers carried by a chip, one of which has exposed evanescent field material carrying a first adsorbent thereon for a first molecular species exposed to said fluid;

directing fluid to be diagnosed from a source thereof to said first adsorbent;

detecting a shift in the heterodyned frequency as an indicator of the presence of said first molecular species in said fluid; and

repeating the foregoing steps with a second pair of lasers carried by said chip having a second adsorbent carried by evanescent field material, whereby to detect a shift in the heterodyned frequency thereof as an indicator of the presence of said second molecular species in said fluid.

23. The method of claim 22, in which fluid to be diagnosed is directed from said first adsorbent to said second adsorbent.

24. The method of claim 22, in which the frequency or wavelength of the reference and sensor lasers are shifted to determine the properties of detected species as a function of wavelength.