Patent US5437840A successfully refreshed from Google Patents.
US5437840A
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US
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Apparatus for intracavity sensing of macroscopic properties of chemicals
Assignee: Agilent Technologies Inc
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Filing: 1994-04-15
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Granted: 1995-08-01
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Expires: 2014-04-15
Abstract
Abstract The presence of trace materials in a sample is detected using both macroscopic and microscopic properties. A detector includes a light source and an optical resonator. The light source may be located either inside the resonance cavity of the resonator or outside the cavity, in which case it may be a semi-conductor such as a semi-conductor laser or a superluminescent diode. The detector also includes at least one reflective member that has a total internal reflection (TIR) surface and may be a passive device or an active gain element. Light from the light source is preferably focussed onto a single point of reflection on the TIR surface. The test sample is positioned within the evanescent field region of the TIR surface. Optical changes arising within the evanescent field region, such as excitation of fluorescence in the sample, changes in its refractive index and changes in the resonant frequency of the optical resonator, are then detected. These changes are then sensed to determine the amount or at least presence of analyte located at the TIR surface.
Inventors
- 👤 David A. King
- 👤 Jens-Peter Seher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:06
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/645; G01N21/648; G01N21/17; G01N21/55; G01N21/552; G01N21/25; G01N21/31; G01N21/39; G01N2021/391; Y; Y10; Y10S; Y10S436/00; Y10S436/805
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
134 words
A device for detecting a target substance in a sample comprising: A. a light source; B. an optical resonator that has a resonance cavity for light generated by the light source; C. a total internal reflection (TIR) member that is located within the resonance cavity and has a TIR surface; in which: D. the light passes into the TIR member and is reflected substantially without loss by the TIR surface, with an angle of incidence greater than a critical angle; E. the sample is positioned to extend within an evanescent field region at the TIR surface; and F. the device further includes detection means for substantially non-absorptively detecting a predetermined macroscopic optical characteristic of the sample corresponding to the amount of the target substance that is in the sample in the evanescent field region.
Claim 2
Independent Claim
134 words
A device for detecting a target substance in a sample comprising: A. a light source; B. an optical resonator that has a resonance cavity for light generated by the light source; C. a total internal reflection (TIR) member that is located within the resonance cavity and has a TIR surface; in which: D. the light passes into the TIR member and is reflected substantially without loss by the TIR surface, with an angle of incidence greater than a critical angle; E. the sample is positioned to extend within an evanescent field region at the TIR surface; and F. the device further includes detection means for substantially non-absorptively detecting a predetermined macroscopic optical characteristic of the sample corresponding to the amount of the target substance that is in the sample in the evanescent field region.
Claim 3
Dependent Claim
22 words
A device as in claim 1, in which there is a single point of reflection for the light at the TIR surface.
Claim 4
Dependent Claim
101 words
A device as in claim 1, in which: A. the resonance cavity has an exit mirror; B. the predetermined macroscopic optical characteristic of the sample is a change in a sample refractive index; and C. the detection means includes intensity sensing and comparison means: 1) for measuring a transmitted intensity of light that exits through the exit mirror; 2) for comparing the transmitted intensity I trans with an incident intensity I inc of the light; and 3) for indicating the presence of the target substance in the sample when the ratio I trans /I inc drops below a predetermined threshold value.
Claim 5
Dependent Claim
79 words
A device as in claim 1, in which: A. the resonance cavity has an exit mirror; B. the predetermined macroscopic optical characteristic of the sample is a change in a sample refractive index; and C. the detection means includes frequency sensing means: 1) for measuring a resonance frequency ω m of the resonance cavity; and 2) for indicating the presence of the target substance in the sample when the resonance frequency ω m drops below a predetermined threshold value.
Claim 6
Dependent Claim
23 words
A device as in claim 1, in which the light source is a gain medium and is positioned outside of the resonance cavity.
Claim 7
Dependent Claim
24 words
A device as in claim 1, in which a binding agent that is specific to the target substance is applied to the TIR surface.
Claim 8
Dependent Claim
29 words
A device as in claim 1, in which the TIR surface is formed by a removable element that is removable from and is optically coupled to the TIR member.
Claim 9
Dependent Claim
15 words
A device as in claim 1, in which the target substance is a trace sample.
Claim 10
Dependent Claim
21 words
A device as in claim 1, in which the TIR surface is formed as an uncladded region of an optical fiber.
Claim 11
Dependent Claim
14 words
A device as in claim 1, in which the TIR surface is a waveguide.
Claim 12
Dependent Claim
14 words
A device as in claim 1, in which the light source is a semi-conductor.
Claim 13
Dependent Claim
16 words
A device as defined in claim 11, in which the light source is a superluminescent diode.
Claim 14
Dependent Claim
16 words
A device as defined in claim 11, in which the light source is a semi-conductor laser.
Claim 15
Dependent Claim
21 words
A device as defined in claim 11, further including optical locking means for frequency-locking the semi-conductor light source to the cavity.
References Cited (Backward Citations)
US4857273A
Cited
US5229833A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-31 | 1999-01-30 | 1999-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-31 | 2003-01-30 | 2003-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-31 | 2007-01-30 | 2007-08-01 | $7700.00 | Window Closed / Lapsed |