Sub-doppler intermodulated laser-induced-fluorescence spectrometer
AssigneeArizona Board of Regents on behalf of Arizona State University
InventorsDamian Kokkin, Timothy Steimle
Life of this patent
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Abstract
Optical spectroscopy system and method possessing spectral selectivity sufficient to distinguish isotopic line of the metal of interest. Each of the light beams, counter-propagating through vial with vapor of the sample, has been originated from the same light output of the laser source and modulated at a corresponding judiciously-determined frequency. The light-output, in turn, possesses a carrier frequency and two side-band frequencies defined with respect to a mean value of excitation frequencies of isotopes in the vapor.
Claims17
An optical system for measuring fluorescence produced by isotopes, the system comprising:
- a frequency-tunable light source configured to generate light output that has a carrier frequency and first and second side-band frequencies;
- an optically-transparent sample vial having a first length and a closed volume, wherein the closed volume is configured to be filled, in operation, with a sample containing a mixture of different isotopes;
- a system of reflectors positioned to direct first and second beams of light, formed from said light output and modulated at respectively-corresponding first and second modulation frequencies, to co-axially counter-propagate in a region of interest (ROI) along the first length to cause co-axially overlapped first and second beams to irradiate the sample at every point of the first length;
- and
- an optical detection unit configured to receive fluorescent light emitted only by isotopes that are stationary in said mixture, said fluorescent light emitted as a result of irradiation of the sample at said every point of the first length with the co-axially overlapped first and second beams.
An optical system according to 8, wherein said electronic circuitry is further configured to generate a report representing spectral distribution intensity of fluorescence produced by the sample.
A method for measuring fluorescence produced by isotopes, the method comprising:
- directing first and second portions of light output, produced by a frequency-tunable light source, towards one another through an optically-transparent vial that has a first length and that is completely filled with a vapor-phase sample formed b a mixture of any number of two or more of different isotopes, to define first and second co-axially counter-propagating beams that overlap at every point of said first length;
- receiving fluorescence, produced only by isotopes that are stationary in said mixture, with an optical detector to form optical data, wherein said fluorescence is emitted as a result of irradiation of the sample at said every point of the first length with the co-axially overlapped first and second beams;
- and
- determining relative abundances of each of the different isotopes contained in said sample based on ratios of areas under curves respectively representing spectral distributions of intensity of fluorescence emitted by the different isotopes, said curves having been generated from said optical data.
Dependencies are inferred from the claim text.