Patent ID: 9606002
Date: 2017-03-28
CPC Classifications: G01J,G01N,H01S

Claim:
1. A method for spectrally analyzing an unknown sample for the existence of a characteristic, the method comprising: analyzing a known sample having the characteristic to identify a plurality of diagnostic spectral features, each diagnostic spectral feature being present at a different diagnostic wavelength that is in a mid-infrared spectral region; providing a spatially homogeneous region of the unknown sample; directing a plurality of interrogation beams at the spatially homogeneous region with a laser source, each of the interrogation beams being nominally monochromatic and having a different interrogation wavelength; wherein each interrogation wavelength corresponds to a different one of the diagnostic wavelengths; acquiring a plurality of separate output images of the unknown sample with an image sensor that senses light in the mid-infrared spectral region, wherein each of the output images is acquired while the unknown sample is illuminated by a different one of the interrogation beams; and analyzing less than fifty output images to analyze whether the characteristic is present in the unknown sample with a control system that includes a processor; wherein the spatially homogeneous region of the unknown sample is substantially structurally homogeneous so that the interrogation wavelengths of the spectral features have shifted less than 10 cm