提高液体中脉冲激光致声转换效率的理论研究

从液体中脉冲激光致声的理论出发,讨论了热膨胀机制下提高光声转换效率的措施,并着重讨论了不同液体媒质的特性对转换效率的影响;基于Helmholtz共振器的共振频率和放大特性理论,讨论了通过共振光声池的设计提高光声转换效率的可行性;指出在对光致声波可重复性和可控制性没有特殊要求的情况下,可采用高功率光纤激光器,通过汽化机制或介电击穿机制激发声波,提高转换效率.

Study of measures to enhance the laser-acoustic conversion efficiency upon the interaction of pulsed laser radiation with liquid

The measures to enhance the laser-acoustic conversion efficiency of laser generation of acoustic waves through thermoelastic mechanism are discussed firstly based on the theory of the interaction of pulsed laser radiation with liquid,and the effects of the characteristic of different liquid media on the conversion efficiency are analyzed specially.And then the feasibility to enhance conversion efficiency using a Helmholtz resonance photoacoustic cell is discussed based on the theory of a Helmholtz resonator which has the capability of amplifying acoustic waves of a certain frequency.At last,when the repeatability and controllability of the acoustic waves are not required strictly,to enhance laser-acoustic conversion efficiency,it is feasible to adopt high-power lasers to induce acoustic waves through vaporization or optical breakdown mechanism.