Abstract: An additive {hacek over (S)}olc filter (ASF) includes i) a first polarizer for receiving an input light, such as from a monochromatic light source, and transmitting a first polarized output, ii) at least one birefringent plate positioned to receive the first polarizer output and transmit an output with wavelength-dependent polarization state, and iii) a second polarizer for receiving the plate output and transmitting a second polarized, filtered output. An ASF spectroscopy system includes the ASF; a monochromatic light source input, e.g. a laser; a sample chamber for exposing a sample to the second polarized, tuned output and generating a signal characteristic of the sample that is filtered by the ASF; and a detector for acquiring the characteristic signal.

Abstract: A scattered-light spectroscopy system for collecting light scattered from a sample, e.g. Raman-scattered light, to produce a spectrum of the sample, includes a cylindrical cell for holding the sample that is transparent and coated on either its inside surface or outside surface with a reflective coating, e.g. aluminum. The reflective coating has an opening for aligning with an aperture in a spectrometer for receiving the sample-scattered light. Light from a source such as a laser illuminates the sample to produce a scattered light having a first part received directly at the opening and a second part reflected by the reflective coating one or more times prior to arrival at the opening, thereby adding to the total scattered light entering the aperture of the spectrometer to improve its collection efficiency.

Abstract: A spectroscopic detector includes a tunable light source, such as a continuously tunable, optical parametric oscillator laser; means for measuring the emitted radiation at a plurality of emission wavelengths to obtain a plurality of spectral measurement data; and a processor for processing the spectral measurement data, where the processor includes a multispectral data processing algorithm or is configured for 1) combining the plurality of spectral measurement data into a composite spectrum, and 2) applying the algorithm to the composite spectrum. The spectra such as resonant and near-resonant Raman Spectra that are acquired are more complete and contain more information. A powerful multispectral analysis code such as IHPS, CHOMPS, or ENN analyzes the acquired data points, examining details of the spectra that could not be handled by traditional methods.

Abstract: A spectroscopic detector includes a tunable light source, such as a continuously tunable, optical parametric oscillator laser; means for measuring the emitted radiation at a plurality of emission wavelengths to obtain a plurality of spectral measurement data; and a processor for processing the spectral measurement data, where the processor includes a multispectral data processing algorithm or is configured for 1) combining the plurality of spectral measurement data into a composite spectrum, and 2) applying the algorithm to the composite spectrum. The spectra such as resonant and near-resonant Raman Spectra that are acquired are more complete and contain more information. A powerful multispectral analysis code such as IHPS, CHOMPS, or ENN analyzes the acquired data points, examining details of the spectra that could not be handled by traditional methods.

Abstract: A spectroscopic detector for identifying the presence of a first substance in the presence of another substance includes a laser for illuminating the substances at a plurality of wavelengths to induce the emission of radiation characteristic of the substance; a spectrometer for measuring the emitted radiation to obtain a plurality of spectral measurement data; and a processor for processing the data. An algorithm combines the data into a composite spectrum and a parameter characteristic of the first substance is identified while information in the composite spectrum contributed by emission of radiation from the other substance is removed to identify the presence of the first substance and obtain a characteristic spectral signature of the first substance. The signature is compared to signatures in a spectral library database, wherein at least some of the library signatures have spectral characteristics differentiated from each other by identifiable spectral characteristics caused by environmental factors.

Abstract: A spectroscopic detector for identifying the presence of a substance includes a laser for illuminating the substance with electromagnetic radiation at a plurality of wavelengths to induce the emission of radiation characteristic of the substance; a spectrometer or photometer for measuring the emitted radiation at a plurality of emission wavelengths to obtain a plurality of spectral measurement data; and a processor for processing the spectral measurement data. The processor includes a processing algorithm configured for combining the plurality of spectral measurement data into a composite spectrum; and applying the algorithm to the composite spectrum whereby at least one parameter characteristic of the substance is identified while information in the composite spectrum contributed by an emission of radiation from any other substance is removed to thereby identify the presence of the substance, and thereby obtain a characteristic spectral signature of the substance.