【摘要】 光束通过瞬态布拉格光栅,其衍射光的强度发生周期性变化,变化频率即为介质密度振荡的频率,由此可以测量介质中的声速.利用光致瞬态光栅测量了常温、常压条件下硝基苯和乙醇中的声速,分别为1 455m/s和1 136m/s,与文献报道结果相符.光学非接触式的声速测量方法,便于与其他装置联合使用,可用于观测高温、高压等极端条件下液体中的声速.更多还原

【Abstract】 When detecting light passed through transient Bragg grating,the intensity of the diffracted light changed periodically,and the frequency was the same as that of the medium density oscillation,thus the sound speed in the medium could be measured.The method to measure the sound speed in nitrobenzene and ethanol at room temperature and normal pressure by using the laser induced transient grating was introduced.The results were 1 455 m/s and 1 136 m/s,respectively,which were in accordance with the reported values.This optical non-contact method was convenient to be combined with other instruments,and could be used to measure the sound speed in liquid materials under high temperature and pressure.更多还原