Konyashkin Aleksey V, Molkov Aleksey A, Ryabushkin Oleg A
Appl Opt. 2020 Oct 1;59(28):8733-8739. doi: 10.1364/AO.403164.
A novel method of acoustic resonance laser calorimetry (ARLC) for the determination of low optical absorption coefficients of crystals and glasses is introduced. It is based on measurements of the kinetics of the equivalent temperature of the sample irradiated by the pulse laser radiation. The equivalent temperature of the sample is directly obtained by measuring the frequency changes of its temperature-calibrated acoustic resonances excited by the laser radiation with a corresponding pulse repetition rate. In contrast to the conventional resonant photoacoustic spectroscopy, where the resonance is used for the enhancement of the registered signal, in ARLC, the laser-excited acoustic resonance of the sample acts as a high-sensitivity temperature probe for measurements of its heating kinetics. The ARLC approach was verified by measuring the optical absorption coefficient of the potassium dihydrogen phosphate crystal (=4.2⋅10) at 1064 nm wavelength.
介绍了一种用于测定晶体和玻璃低光吸收系数的新型声共振激光量热法（ARLC）。它基于对脉冲激光辐射照射下样品等效温度动力学的测量。通过测量以相应脉冲重复率由激光辐射激发的其温度校准声共振的频率变化，直接获得样品的等效温度。与传统的共振光声光谱法不同，在传统方法中共振用于增强记录信号，而在ARLC中，样品的激光激发声共振用作测量其加热动力学的高灵敏度温度探针。通过测量磷酸二氢钾晶体在1064nm波长处的光吸收系数（=4.2⋅10）验证了ARLC方法。
