Abstract: This invention relates to a system and method to improve the signal to noise ratio (SNR) of optical spectrometers that are limited by nonrandom or fixed pattern noise. A signal from a sample is collected using a short test exposure, a total observation time to maximize SNR is calculated, and the total observation time is achieved by averaging multiple exposures whose time is selected based on the time dependent noise structure of the detector. Moreover, with a priori knowledge of the time dependent noise structure of the spectrometer, this method is easily automatable and can maximize SNR for a spectrum of an unknown compound without any user input.

Abstract: A device for analyzing the material composition of a sample via plasma spectrum analysis includes a laser assembly configured to emit a beam for plasma spectrum analysis and an optical assembly configured to direct the beam towards a target for plasma spectrum analysis of the target. The optical assembly is configured to collect a plasma emitted light emitted from a plasma and provide the plasma emitted light to a dispersion module. The dispersion module includes a first and second diffraction gratings. The first diffraction grating and second diffraction grating are positioned within the dispersion module such that light received from the optical assembly contacts the first diffraction grating at least two times before being directed out of the dispersion module.

Abstract: Apparatus and methods of spectral searching that employ wavelet coefficients as the basis for the searching. The disclosed apparatus and methods employ a wavelet lifting scheme to transform spectroscopic data corresponding to an unknown pure material/mixture to a vector of wavelet coefficients, compare the wavelet coefficient vector for the unknown pure material/mixture with a library of wavelet coefficient vectors for known pure materials/mixtures, and identify the closest match to the unknown pure material/mixture based on the comparison of wavelet coefficient vectors.