Forward degenerate four-wave mixing based isotope detection method with ultrahigh sensitivity

Abstract

The invention discloses an FDFWM (forward degenerate four-wave mixing) based isotope detection method with an ultrahigh sensitivity. The method comprises the following steps: a laser beam is divided into three light beams with a same light path; space positions of the three light beams are adjusted; the three light beams are focused and interacted with an isotope sample to be detected on a focusing point to generate an FDFWM signal; a center frequency of a laser is scanned, and a photoelectric detector is employed to measure the FDFWM signal of the isotope sample to be detected, so as to obtain an FDFWM signal spectrum, which changes with the laser center frequency, of the FDFWM signal; and content information of the isotope sample to be detected is obtained according to the FDFWM signal spectrum. The method of the invention can increase a sensitivity of an isotope detection and realize near nondestructive test; if the method of the invention is employed to detect an isotope, a detection limit is lowered, and a sampling amount is reduced; besides, the method has advantages of relative simple equipment, convenient operation, and ultrahigh sensitivity and detection precision.

Description

technical field [0001] The invention belongs to the category of nonlinear spectroscopy technology, and relates to an isotope detection method, in particular to an ultrahigh-sensitivity isotope detection method based on forward degenerate four-wave mixing (FDFWM). Background technique [0002] Isotope analysis has important applications in geology, archaeology, nuclear technology, biomedical tracing, environmental science and other fields. Isotope analysis is a major method for dating rocks and geological events. With the help of U-Pb, K-Ar, Rb-Sr and some other isotopes used for age determination, it provides a time-series study of geological events or processes. data of. Similarly, isotope dating technology also has obvious significance in archeology, such as: C-14 dating method, Pb isotope ratio method to measure the age of cultural relics and the method of origin. In the nuclear industry, people monitor the burnup in the nuclear fuel cycle by analyzing the identificatio...

AI Technical Summary

Problems solved by technology

However, mass spectrometry has many shortcomings, such as high cost, complicated sample pretreatment, and long detection time.

Mass spectrometry consumes a large amount of sample (microgram level), which makes it far from meeting the requirements of non-destructive and near-non-destructive testing, such as precious cultural relics, etc.

Another fatal flaw of mass spectrometry is isobaric element interference, which makes many isotopes unable to be resolved (Dominic Lariviere, Vivien F. Taylor, R. Douglas Evans, R. Jack Cornett. Spectrochimica. Acta Part B 2006, 61 877.)

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