Abstract: A method based on time-resolved, laser-induced fluorescence spectroscopy for the characterization and fingerprinting of petroleum oils and other complex mixtures. The method depends on exciting the wavelength-resolved fluorescence spectra of samples using ultraviolet pulsed laser radiation, measuring them at specific time gates within the temporal response of the excitation laser pulse, and comparing them in terms of their shapes alone without taking into account their relative intensities. The method provides fingerprints of crude oils without resorting to any kind of approximation, for distinguishing between closely similar crude oils of the same grade, and is useful in remote and non-remote setups, along with applications in fingerprinting blended and non-blended crude oils using different ultraviolet excitation wavelengths. Applications include estimating ∘API gravity of crude oils and monitoring degradation of mineral oils.

Abstract: A method based on time-resolved, laser-induced fluorescence spectroscopy for the characterization and fingerprinting of petroleum oils and other complex mixtures. The method depends on exciting the wavelength-resolved fluorescence spectra of samples using ultraviolet pulsed laser radiation, measuring them at specific time gates within the temporal response of the excitation laser pulse, and comparing them in terms of their shapes alone without taking into account their relative intensities. The method provides fingerprints of crude oils without resorting to any kind of approximation, for distinguishing between closely similar crude oils of the same grade, and is useful in remote and non-remote setups, along with applications in fingerprinting blended and non-blended crude oils using different ultraviolet excitation wavelengths. Applications include estimating °API gravity of crude oils and monitoring degradation of mineral oils.

Abstract: Two laser beams of different frequencies are combined to form a composite carrier beam of a frequency midway between those of the individual beams and modulated at the beat frequency between the individual beams. This composite beam can be used in a variety of ways, such as to irradiate a workpiece, the electro-optical frequency response characteristics of which are to be studied. By using an autocorollation technique the range of frequency over which these characteristics can be studied has for the first time been greatly expanded, well up into the terahertz range. Other applications of the equipment include the fine measurement of distances in the micrometer to meter range and secure digital transmission of data on a laser beam.