FREQUENCY AND INTENSITY MODULATION LASER ABSORPTION SPECTROSCOPY APPARATUS AND THE MEASURING METHOD OF THE SAME

摘要

Provided are an optical frequency and intensity modulation laser absorption spectroscopy apparatus and an optical frequency and intensity modulation laser absorption spectroscopy method. The optical frequency and intensity modulation laser absorption spectroscopy apparatus comprises: a full-field light source for outputting a field beam of a visible band; a frequency and intensity modulation spectroscopy processing unit for modulating the optical frequency of a laser beam with a modulation frequency (fm), modulating the intensity of the laser beam with the modulation frequency (fm) to output a probe beam, converting a laser absorption signal, which is generated by the resonance absorption of a measurement target receiving the probe beam, into an electrical signal, and extracting a first harmonic component and a second harmonic component of the modulation frequency (fm) from the converted laser absorption signal; a beam processing unit for providing an object lens with the field beam and the probe beam; and the object lens for providing the measurement target with the field beam as full-field light and focusing the probe beam at the focal point thereof to provide the measurement position of the measurement target with the focused probe beam. The apparatus of the present invention can accurately quantify the absorbance of the measurement target.