DIELECTRIC MICROCAVITY FLUOROSENSORS EXCITED WITH A BROADBAND LIGHT SOURCE

• US 20070284513A1
• Filed: 08/23/2007
• Published: 12/13/2007
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wilson, Robert, Guo, Chunmei, Fan, Xudong
• Granted Patent: US 7,622,705 B2
• Time in Patent Office: Days
• US Class Current: 250/216
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G02B 6/29341 Loop resonators operating in a whispering gallery mode evanescently coupled to a light guide, e.g. sphere or disk or cylinder evanescent coupling for sensing fluorescence G01N21/648
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures

Abstract

A microresonator sensor apparatus has a microcavity resonator that defines equatorial whispering gallery modes (EWGMs), whose frequencies are separated by the free spectral range (FSR). The EWGMs lie in a plane perpendicular to a microcavity resonator axis. A light source is optically coupled to inject light into the microcavity resonator. The light source produces output light having an output spectrum whose bandwidth is approximately equal to or broader than the FSR of the EGWMs. One or more fluorescent materials are excited using the excitation light coupled into the microcavity resonator. A fluorescent signal arising from fluorescence of the one or more fluorescent materials is then detected.

Claims

1. A microresonator apparatus, comprising:

a microcavity resonator capable of supporting multiple resonant modes;

a light source optically coupled to the microcavity resonator and capable of simultaneously exciting the multiple resonant modes;

a fluorescent material optically coupled to the microcavity resonator;

a first detector disposed to detect light from the microcavity resonator; and

a second detector disposed to detect fluorescent light produced by the fluorescent material.

2. The microresonator apparatus of claim 1, wherein the multiple resonant modes comprise at least two whispering gallery modes (WGMs).

3. The microresonator apparatus of claim 2, wherein the at least two WGMs comprise at least two adjacent WGMs.

4. The microresonator apparatus of claim 2, wherein the at least two WGMs comprise at least two equatorial whispering gallery modes (EWGMs).

5. The microresonator apparatus of claim 1, wherein the light source is optically coupled to the microcavity resonator via an optical waveguide.

6. The microresonator apparatus of claim 5, wherein the optical waveguide comprises a tapered fiber.

7. The microresonator apparatus of claim 1, wherein the light source comprises a light emitting diode.

8. The microresonator apparatus of claim 1, wherein the second detector detects the fluorescent light propagating in free space from the fluorescent material.

9. The microresonator apparatus of claim 1 further comprising an analyte optically coupled to the microcavity resonator and the fluorescent material.

10. The microresonator apparatus of claim 1, wherein the multiple resonant modes comprise at least five resonant modes.

11. The microresonator apparatus of claim 1, wherein the multiple resonant modes comprise at least ten resonant modes.