Apparatus and method for spectroscopic analysis of scattering media

• US 5,303,026 A
• Filed: 02/12/1992
• Issued: 04/12/1994
• Est. Priority Date: 02/26/1991
• Status: Expired due to Term

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Loree, Thomas R., Bigio, Irving J., Strobl, Karlheinz
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US07/835,641
• Time in Patent Office: 790 Days
• Field of Search: 356/73, 356/317, 356/318, 356/417, 250/458.1, 250/459.1, 250/461.1, 250/461.2, 128/395, 128/398, 128/665
• US Class Current: 356/318
• CPC Class Codes: G01J 2001/1636 one detector directly monitoring the source, e.g. also impulse time controlling
• CPC Class Codes: G01J 3/4406 Fluorescence spectrometry
• CPC Class Codes: G01N 2021/6419 Excitation at two or more wavelengths
• CPC Class Codes: G01N 2021/6421 Measuring at two or more wavelengths
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 2201/0696 Pulsed
• CPC Class Codes: G01N 2201/08 Optical fibres; light guides

Abstract

Apparatus and method for spectroscopic analysis of scattering media. Subtle differences in materials have been found to be detectable from plots of intensity as a function of wavelength of collected emitted and scattered light versus wavelength of excitation light.

Claims

1. An apparatus for recording the optical responses of biological tissue, comprising in combination:

a. wavelength-tunable light generation means for rapidly generating high-brightness multiple wavelengths of light within a chosen range of wavelengths;

b. fiber-optic means for collecting the light generated from said light generation means and for directing the light into a small volume of the biological tissue under investigation;

c. detection means for receiving and for rapidly detecting light; and

d. fiber-optic means for collecting the light emitted and scattered from the biological tissue and for directing the emitted and scattered light into said detection means, said means for collecting the generated light and said fiber-optic means for collecting the emitted and scattered light being disposed in a substantially parallel manner in the proximity of one another and in contact with the biological tissue, whereby light emitted, transmitted and scattered by the biological tissue is measured.

2. The apparatus as described in claim 1, further comprising light intensity sampling means for determining the output intensity of said light generation means at every wavelength generated thereby.

3. The apparatus as described in claim 1, wherein said light generation means comprises a pulsed xenon arc lamp in cooperation with a rapidly tunable monochromator.

4. The apparatus as described in claim 1, wherein said light generation means comprises a tunable, laser-driven nonlinear optical oscillator.

5. The apparatus as described in claim 1, wherein said light generation means includes laser means.

6. A method for recording spectroscopic information from a sample, comprising the steps of:

a. rapidly generating high-brightness multiple wavelengths of light within a chosen range of wavelengths;

b. collecting the generated light and directing the light into a small volume of the sample under investigation; and

c. collecting and rapidly detecting substantially all wavelengths of light emitted and scattered at the surface of the small volume emerging from the sample in the opposite direction from the incident light resulting from the interaction of the sample with the light incident thereon;

whereby light emitted, scattered, and transmitted by the sample in response to the incident wavelengths of radiation is observed.

7. The method as described in claim 6, further comprising the step of determining the output intensity of light generated at every wavelength generated in said step of light generation.