DEVICE FOR QUANTITATIVELY DETECTING CARBON-14 ISOTOPE USING DOUBLE-WAVELENGTH METHOD, AND SPECTROMETER

A device and a spectrometer for quantitatively detecting carbon 14 isotope by a dual-wavelength method. Two mid-infrared lasers with different wavelengths are locked in an optical cavity of a sample chamber (15), to ensure the two lasers are collinear. The cavity length of the optical cavity is adjusted by a cavity length adjusting unit (17), to tune the mode frequency of the optical cavity, and then tune the frequencies of the two mid-infrared lasers, so that the frequencies of the two mid-infrared lasers match with different energy levels of the target isotope molecule simultaneously. After the frequencies of the mid-infrared lasers match with the energy levels of the target isotope molecule simultaneously, the target isotope molecule is excited by two mid-infrared lasers simultaneously, and the optical cavity output signal of the second mid-infrared laser passing through the optical cavity is detected. That is to say, since the excitation of the target isotope molecule and the detection of the spectrum require two lasers to match with different energy levels of the target isotope molecule simultaneously, it greatly improves the selectivity of the spectral detection, thereby improving the spectral resolution ability, i.e., achieving the selection and resolution of the target isotope molecule.