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当物体某部分温度起伏时,发生热弹振动并发射弹性波,称为热弹波(Thermal wave或Thermoelastic wave)。热弹波的应用是很广泛的。热能的变化可以是不同类型的能量转换而来,不同形式的能都有可能成为热弹波的能源,其中光能是很早以前就被发现并用作热弹波的能源的,最近又有用扫描电镜的电子束作能源来照射样品产生热弹波从而成像的实验,因而,除电镜显微像外,同时又获得一种新信息——热弹像。 一束强度被调制的光束照射在样品上,产生频率与调制频率相同的声波(即热弹波),这一现象称为光声效应(Photoacoustic effect)。当然光能变为声能的过程中是经过了热能这个阶段的,而且反映了样品的吸收光谱特性。早期光吸收谱的研究仅限于透光物质,自1880年光声
When a part of the object fluctuates in temperature, a thermo-elastic vibration occurs and an elastic wave is emitted, which is called a thermal wave or a thermoelastic wave. The application of thermal wave is very wide. Changes in thermal energy can be different types of energy conversion, different forms of energy are likely to become the energy source of thermal energy, which was discovered a long time ago and used as a thermal energy of the heat wave, the recent useful scan Electron electron beam as an energy source to irradiate the sample to generate thermal shock imaging experiment, therefore, in addition to microscopic electron microscopy, but also to obtain a new information - thermal elastography. A beam of light with a modulated intensity is applied to the sample to produce a sound wave of the same frequency as the modulation frequency (ie, thermal shock), a phenomenon known as the photoacoustic effect. Of course, the process of light energy into sound energy is through the heat of this stage, but also reflects the absorption spectrum characteristics of the sample. Early studies of light absorption spectra were limited to translucent matter, photoacoustic since 1880