Identification and analysis of materials and molecular structures

• US 9,599,565 B1
• Filed: 10/02/2013
• Issued: 03/21/2017
• Est. Priority Date: 10/02/2013
• Status: Active Grant

• Current Assignee: Coherent Inc (Coherent Corp.)
• Original Assignee: Ondax Incorporated (Coherent Corp.)
• Inventors: Carriere, James, Ho, Lawrence, Havermeyer, Frank, Maye, Eric, Heyler, Randy
• Primary Examiner(s): Gray, Sunghee Y
• Application Number:
  US14/044,773
• Time in Patent Office: 1,266 Days
• Field of Search: 356/301
• US Class Current: 1/1
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G01N 2201/068 Optics, miscellaneous

Abstract

Provided are methods and systems for identification and analysis of materials and molecular structures. An apparatus for identification and analysis of materials and molecular structures may include a laser. The laser may, in turn, include an amplified spontaneous emission-suppressed single-frequency laser excitation source. The apparatus may further comprise a plurality of filters. The plurality of filters may include reflective volume holographic grating blocking filters. The apparatus may also comprise an optical unit and an optical spectrometer. The optical unit may be configured to deliver excitation energy to a sample substance and capture Raman signal scattering from the sample substance. The optical spectrometer may be disposed in a path of the Raman signal and configured to measure a spectrum of the Raman signal and generate a detection signal. Finally, the apparatus may comprise a processing unit configured to analyze the spectrum.

Claims

1. A method for identification and analysis of materials and molecular structures, the method comprising:

providing a laser excitation source;

providing a plurality of filters, the plurality of filters including reflective blocking filters with a transition width of <

50 cm<sup>−

1</sup>;

providing at least one optical unit configured to deliver excitation energy to a sample substance and to capture Raman signal scattering from the sample substance, the captured Raman signal being at least in a spectral range of +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup>;

providing an optical spectrometer configured to measure a spectrum of the Raman signal and generate a detection signal, the optical spectrometer being disposed in a path of the Raman signal; and

providing a processing unit configured to analyze the captured Raman signal within a +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup> portion of a spectrum of the sample substance, the analyzing of the +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup> portion of the spectrum of the sample substance including measuring changes to peak shape and peak locations,

the peak shape and peak locations being associated with structural characteristics and/or changes in form.

2. The method of claim 1, wherein the plurality of reflective blocking filters have a cumulative optical density of at least 4.

3. The method of claim 1, wherein the laser source is an ASE-suppressed laser.

4. The method of claim 1, wherein the optical spectrometer is configured to also collect Raman spectra in a fingerprint region.

5. The method of claim 1, wherein the sample substance includes at least one of a polymorphic, polyamorphous, allotropic, isomeric, isotopologous, cocrystalline, or conformational element, compound or substance.

6. The method of claim 1, wherein the sample substance includes a pharmaceutical or biopharmaceutical compound, an explosive agent, a biological substance, a cellular substance, a chemically hazardous substance, a radiological substance, a mineralogical substance, a nuclear material, a radiological material, a semiconductor material, a photovoltaic material, or an electronic material.

7. The method of claim 1, wherein the laser, the plurality of filters, and the optical spectrometer are configured as individual units optically coupled to each other.

8. The method of claim 1, wherein the laser and the plurality of filters are configured as a single unit optically coupled to the optical spectrometer.

9. The method of claim 1, wherein the laser, the plurality of filters, and the optical spectrometer are configured as a single unit.

10. The method of claim 1, wherein the plurality of filters and the optical spectrometer are configured as a single unit and the laser is optically coupled to the single unit.

11. The method of claim 1, wherein the plurality of filters include at least one volume holographic grating blocking filter.

12. The method of claim 1, wherein the structural characteristics and/or changes in form include at least one of:

phonon vibrational modes;

polymorphic, allotropic, isomeric, conformational, isotopologic, or cocrystalline forms;

amorphous and crystalline phases and phase changes;

crystalline orientation;

cocrystalline composition;

rotational modes;

physical properties;

temperature;

strain or defects;

methods of manufacture; and

environmental exposure.

13. A method for identification and analysis of materials and molecular structures comprising:

providing a laser excitation source;

providing a plurality of filters, the plurality of filters including reflective blocking filters with a transition width of <

50 cm<sup>−

1</sup>;

providing at least one optical unit delivering excitation energy to a sample substance and capturing a Raman signal scattering from the sample substance, the captured Raman signal being at least in a spectral range of +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup>;

providing an optical spectrometer disposed in a path of the Raman signal, the optical spectrometer measuring a spectrum of the Raman signal and generating a detection signal, the optical spectrometer simultaneously collecting low-frequency Stokes and anti-Stokes Raman spectra, the low-frequency Stokes and anti-Stokes Raman spectra being in +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup> Raman spectrum; and

providing a processing unit configured to analyze the captured Raman signal within a +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup> portion of a spectrum of the sample substance, the analyzing of the +20 cm<sup>−

1</sup> to +200 cm<sup>−

1</sup> and −

20 cm<sup>−

1</sup> to −

200 cm<sup>−

1</sup> portion of the spectrum of the sample substance including measuring changes to peak shape and peak locations associated with structural characteristics and/or changes in form.

14. The method of claim 13 further comprising:

adding complementary components of the low-frequency Stokes and anti-Stokes Raman spectra to boost an overall signal, the optical spectrometer measuring a spectrum of the overall signal.

15. The method of claim 13, wherein the plurality of reflective blocking filters have a cumulative optical density of at least 4.

16. The method of claim 13, wherein the laser source is an ASE-suppressed laser.

17. The method of claim 13, wherein the optical spectrometer further collects Raman spectra in a fingerprint region.

18. The method of claim 13, wherein the sample substance includes at least one of a polymorphic, polyamorphous, allotropic, isomeric, isotopologous, cocrystalline, or conformational element, compound or substance.

19. The method of claim 13, wherein the sample substance includes a pharmaceutical or biopharmaceutical compound, an explosive agent, a biological substance, a cellular substance, a chemically hazardous substance, a radiological substance, a mineralogical substance, a nuclear material, a radiological material, a semiconductor material, a photovoltaic material, or an electronic material.

20. The method of claim 13, wherein the structural characteristics and/or changes in form include at least one of:

phonon vibrational modes;

polymorphic, allotropic, isomeric, conformational, isotopologic, or cocrystalline forms;

amorphous and crystalline phases and phase changes;

crystalline orientation;

cocrystalline composition;

rotational modes;

physical properties, temperature;

strain or defects;

methods of manufacture; and

environmental exposure.

21. The method of claim 13, wherein the laser, the plurality of filters, and the optical spectrometer are individual units optically coupled to each other.

22. The method of claim 13, wherein the laser and the plurality of filters are optically coupled to the optical spectrometer as a single unit.

23. The method of claim 13, wherein the laser, the plurality of filters, and the optical spectrometer are a single unit.

24. The method of claim 13, wherein the plurality of filters and the optical spectrometer are a single unit and the laser is optically coupled to the single unit.

25. The method of claim 13, wherein the plurality of filters include at least one volume holographic grating blocking filter.