Patent ID: 8184293

Claim:
A spectroscopic system for detecting electromagnetic radiation that has passed through or is reflected from a sample, the system comprising: an electromagnetic radiation source; a rotatable filter assembly configured to filter a beam of electromagnetic radiation produced by the electromagnetic radiation source prior to the electromagnetic radiation passing through or onto the sample, said assembly comprising one or more bandpass optical interference filters, wherein the rotatable filter assembly is configured to rotate to provide continuous adjustment of the incident angle of the electromagnetic beam onto the one or more optical interference filters, thereby providing a continuous wavelength sweep in a single wavelength band or multiple wavelength bands, and wherein one or more of the bandpass filters is configured such that the filter is angularly tilted forming a nonzero angle between an axis perpendicular to the axis of rotation of the rotatable filter assembly and an axis normal to the surface of the filter; a motor coupled to the rotatable filter assembly; an electromagnetic radiation detector configured to detect electromagnetic radiation that has passed through or is reflected from the sample; and a processor configured to process a spectral data signal from the electromagnetic radiation detector to produce chemical information about the sample.