received by the International Bureau on 27 June 2018 (27.06.2018)

5 1. A method of measuring Raman scattering from a sample, comprising: exciting Raman scattering of a sample with a first wavelength of electromagnetic radiation traveling along an optical path to form a first scattered radiation, wherein the first wavelength is provided to the sample polarized in a first direction; exciting Raman scattering of the sample with a second wavelength of electromagnetic 10 radiation traveling along the optical path to form a second scattered radiation, wherein the second wavelength is different than the first wavelength, and wherein the second wavelength is provided to the sample polarized in a second direction perpendicular to the first direction;

collecting a first Raman spectrum from the first scattered radiation;

15 collecting a second Raman spectrum from the second scattered radiation; and

interpolating between the first Raman spectrum and the second Raman spectrum to form a decomposed Raman spectrum based on the first Raman spectrum and the second Raman spectrum.

20 2. The method of claim 1, wherein exciting Raman scattering of the sample at a second wavelength comprises exciting Raman scattering of the sample at a second wavelength within 10 nm of the first wavelength.

3. The method of claim 1, wherein exciting Raman scattering of a sample with 25 a first wavelength of electromagnetic radiation comprises maintaining a constant

temperature of a first electromagnetic source configured to emit the first wavelength and wherein exciting Raman scattering of the sample with a second wavelength of electromagnetic radiation comprises maintaining a constant temperature of a second electromagnetic source configured to emit the second wavelength. 22

4. The method of any one of claims 1 through 3, further comprising changing a polarization of at least one of the first scattered radiation or the second scattered radiation.

5. The method of claim 4, wherein changing a polarization of at least one of the first scattered radiation or the second scattered radiation comprises passing at least one of the first scattered radiation or the second scattered radiation through a half- wave plate.

6. The method of claim 5, wherein passing at least one of the first scattered radiation or the second scattered radiation through a half-wave plate comprises collecting at least a third Raman spectrum from the first scattered radiation or the second scattered radiation.

7. The method of claim 6, further comprising comparing the at least a third Raman spectrum with the first Raman spectrum or the second Raman spectrum to discriminate the Raman spectra from fluorescence.

8. The method of claim 6, wherein forming a decomposed Raman spectrum comprises forming a decomposed Raman spectrum based on the first Raman spectrum, the second Raman spectrum, and the at least a third Raman spectrum.

9. The method of claim 5, wherein:

collecting a first Raman spectrum from the first scattered radiation comprises passing the first scattered radiation through the half-wave plate in a first position; and collecting a second Raman spectrum from the second scattered radiation comprises passing the second scattered radiation through the half-wave plate in a second position.

10. The method of claim 5, wherein passing at least one of the first scattered radiation or the second scattered radiation through a half-wave plate comprises passing at least one of the first scattered radiation or the second scattered radiation through an electro- optic polarization rotator. 23

1 1. The method of any one of claims 1 through 3, wherein forming a decomposed Raman spectrum comprises interpolating between the first Raman spectrum and the second Raman spectrum. 12. The method of any one of claims 1 through 3,

wherein exciting Raman scattering of a sample with a first wavelength of electromagnetic radiation comprises:

passing a first beam through a first polarizing device to form a first linear polarized beam; and

passing the first linear polarized beam to a beam combiner;

wherein exciting Raman scattering of the sample with a second wavelength of

electromagnetic radiation comprises:

passing a second beam through a second polarizing device to form a second linear polarized beam having a polarization orthogonal to a polarization of the first linear polarized beam; and

passing the second linear polarized beam to the beam combiner.

13. The method of any one of claims 1 through 3, further comprising changing polarization of an excitation source that provides at least one of the first wavelength and the second wavelength of electromagnetic radiation.

14. A laser device, comprising:

a first electromagnetic source adapted to provide a first beam having a first wavelength; a second electromagnetic source adapted to provide a second beam having a second

wavelength different from the first wavelength, wherein a difference between the first wavelength and the second wavelength is less than 10 nm;

a first polarized device configured to convert the first beam to a first polarized beam; a second polarized device configured to convert the second beam to a second polarized beam; and

a beam combiner configured to combine the first polarized beam and the second polarized beam to form orthogonal collinear polarized beams traveling along a common optical path. 24

15. (canceled)

16. The laser device of claim 14, wherein a difference between the first wavelength and the second wavelength is approximately 2 nm.

17. The laser device of claim 16, wherein the first wavelength is approximately 785 nm and the second wavelength is approximately 783 nm. 18. The laser device of any one of claims 14 through 17, wherein each of the first polarized device and the second polarized device comprises a quarter-wave plate.

19. The laser device of any one of claims 14 through 17, further comprising at least one temperature regulator configured to maintain at least one of the first

electromagnetic source and the second electromagnetic source at a constant temperature while the first electromagnetic source or the second electromagnetic source provides the first beam or the second beam.

20. The laser device of claim 19, wherein the at least one temperature regulator comprises a thermoelectric device.

21. The laser device of any one of claims 14 through 17, further comprising a half-wave plate configured to receive scattered radiation from the test sample. 22. The laser device of claim 21, wherein the half-wave plate comprises an electro-optic polarization rotator.

23. The laser device of any one of claims 14 through 17, further comprising a half-wave plate configured to change a polarization of at least one of the first beam and the second beam. 25

24. The laser device of any one of claims 14 through 17, wherein each of the first electromagnetic source and the second electromagnetic source comprise a volume Bragg grating. 25. A spectrometer, comprising:

the laser device of any one of claims 14 through 17; and

a detector adapted to receive scattered radiation from the test sample and detect a

spectroscopy signal from the scattered radiation.