Claims
- 1. A method for measuring one or more optical properties of a test medium, comprising:
providing an optical waveguide loop comprising a test medium; illuminating the optical waveguide loop with a plurality of light pulses; and detecting roundtrips of said light pulses at one or more locations along the loop; wherein said detected light pulses are indicative of one or more optical properties of the test medium.
- 2. The method of claim 1, further comprising determining ring-down time of said light pulses.
- 3. The method of claim 1, wherein the optical waveguide loop is passive.
- 4. The method of claim 2, wherein a period between light pulses is greater than the ring-down time of a light pulse.
- 5. The method of claim 4, wherein the ring-down time is determined by summing the roundtrips for light pulses at each instance in time.
- 6. The method of claim 4, further comprising providing light pulses of smaller pulse width and/or a longer waveguide loop, such that roundtrips from each light pulse are separated in time.
- 7. The method of claim 5, further comprising providing light pulses of greater pulse width and/or a shorter waveguide loop, such that an envelope of the ring-down time is measured.
- 8. The method of claim 2, wherein a period between light pulses is less than the ring-down time of a light pulse.
- 9. The method of claim 8, wherein the ring-down time is determined from an integrated waveform corresponding to the sum of ring-down waveforms for the light pulses.
- 10. The method of claim 8, further comprising providing light pulses of smaller pulse width and/or a longer waveguide loop, such that roundtrips from each light pulse are separated in time.
- 11. The method of claim 8, further comprising providing light pulses of greater pulse width and/or a shorter waveguide loop, such that an envelope of the ring-down is measured.
- 12. The method of claim 1, wherein the optical waveguide is an optical fiber.
- 13. The method of claim 12, wherein the optical waveguide further comprises a fiber optic splice connector.
- 14. The method of claim 12, wherein the optical waveguide further comprises a fusion spliced connection.
- 15. The method of claim 1, wherein the waveguide loop is the test medium.
- 16. The method of claim 1, wherein the test medium is exposed to light that is guided by the optical waveguide loop using a capillary flow channel.
- 17. The method of claim 1, wherein the test medium is in the vicinity of the optical waveguide and is exposed an evanescent wave of light that is guided by the optical waveguide loop.
- 18. The method of claim 1, wherein the optical property is absorbance.
- 19. The method of claim 1, wherein the optical property is refractive index.
- 20. The method of claim 1, wherein the light pulses have at least one wavelength selected from infra-red (IR), visible, and ultra-violet.
- 21. The method of claim 1, the number of light pulses is between about 10 and 10,000.
- 22. The method of claim 1, wherein the test medium is selected from a gas, a liquid, and a solid material.
- 23. A method for measuring one or more optical properties of a test medium, comprising:
providing an optical waveguide loop comprising a test medium; and measuring ring-down time of a plurality of light pulses travelling around the loop and through the test medium; wherein the ring-down time is indicative of one or more optical properties of the test medium.
- 24. The method of claim 23, wherein the optical waveguide loop is passive.
- 25. An apparatus for measuring one or more optical properties of a test medium, comprising:
an optical waveguide loop comprising a test medium; a light source for illuminating the loop with a plurality of light pulses; and a detector for detecting roundtrips of said light pulses at one or more locations along the loop; wherein said detected light pulses are indicative of one or more optical properties of the test medium.
- 26. The apparatus of claim 25, further comprising a device for displaying and/or storing and/or manipulating data corresponding to light pulses.
- 27. The apparatus of claim 25, wherein ring-down time of said light pulses is determined.
- 28. The apparatus of claim 25, wherein the optical waveguide loop is passive.
- 29. The apparatus of claim 27, wherein a period between light pulses is greater than the ring-down time of a light pulse.
- 30. The apparatus of claim 29, wherein the ring-down time is determined by summing the roundtrips for light pulses at each instance in time.
- 31. The apparatus of claim 29, further comprising providing light pulses of smaller pulse width and/or a longer waveguide loop, such that roundtrips from each light pulse are separated in time.
- 32. The apparatus of claim 29, further comprising providing light pulses of greater pulse width and/or a shorter waveguide loop, such that an envelope of the ring-down time is measured.
- 33. The apparatus of claim 27, wherein a period between light pulses is less than the ring-down time of a light pulse.
- 34. The apparatus of claim 33, wherein the ring-down time is determined from an integrated waveform corresponding to the sum of ring-down waveforms for the light pulses.
- 35. The apparatus of claim 33, further comprising providing light pulses of smaller pulse width and/or a longer waveguide loop, such that roundtrips from each light pulse are separated in time.
- 36. The apparatus of claim 33, further comprising providing light pulses of greater pulse width and/or a shorter waveguide loop, such that an envelope of the ring-down is measured.
- 37. The apparatus of claim 25, wherein the optical waveguide is an optical fiber.
- 38. The apparatus of claim 37, wherein the optical waveguide further comprises a fiber optic splice connector.
- 39. The apparatus of claim 33, wherein the optical waveguide further comprises a fusion spliced connection.
- 40. The apparatus of claim 25, wherein the waveguide loop is the test medium.
- 41. The apparatus of claim 25, wherein the test medium is exposed to light that is guided in by the optical waveguide loop using a capillary flow channel.
- 42. The apparatus of claim 25, wherein the test medium is in the vicinity of the optical waveguide and is exposed an evanescent wave of light that is guided by the optical waveguide loop.
- 43. The apparatus of claim 25, wherein the optical property is absorbance.
- 44. The apparatus of claim 25, wherein the optical property is refractive index.
- 45. The apparatus of claim 25, wherein the light pulses have at least one wavelength selected from infra-red (IR), visible, and ultra-violet.
- 46. The apparatus of claim 25, the number of light pulses is between about 10 and 10,000.
- 47. The apparatus of claim 25, wherein the test medium is selected from a gas, a liquid, and a solid material.
- 48. The apparatus of claim 25, wherein the optical property is absorbance and the apparatus further comprises a microfluidic device.
- 49. An apparatus for measuring one or more optical properties of a test medium, comprising:
an optical waveguide loop comprising a test medium; a light source for illuminating the loop with a plurality of light pulses; a detector for detecting roundtrips of said light pulses at one or more locations along the loop; and a device for displaying and/or storing and/or manipulating data corresponding to light pulses; wherein ring-down time of said light pulses is determined; and wherein said ring-down time is indicative of one or more optical properties of the test medium.
- 50. The apparatus of claim 49, wherein the optical waveguide loop is passive.
RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/331,181, filed on Nov. 9, 2001, and of U.S. Provisional Patent Application No. 60/293,518, filed on May 29, 2001, the disclosures of which are incorporated herein by reference in their entirety.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60331181 |
Nov 2001 |
US |
|
60293518 |
May 2001 |
US |