Measuring thermal diffusivity of solid materials by laser optical beam deflection method

本文介绍了激光光束偏转法测量材料热扩散率的原理，从理论上分析了光的粒子性和光的衍射限制了该方法对热扩散率的测量精度，指出了提高测量精度的关键在于提高信号对光束偏转的灵敏度。为此给出了一种带有Ronchi光栅的迈克耳孙干涉仪的探测装置，从而使灵敏度提高了约5.3倍。The measurement principle of thermal diffusivity of material by laser optical beam defection method(OBDM) is described. Due to the particle of light and the diffraction of light, some limits of the prectision are analyzed theoretically for measuring thermal deffusivity by OBDM in this paper. For increasing the measurement precision, the key is to increase the sensitivity for optical beam deflection. A Michelson interferometer with a Ronchi grating as the detecton scheme has been implemented. In this case, the amplification in sensitivity was approximately 3.5 times