多级声光衍射相互作用长度的实验研究

Experimental research on the interaction length of multi-order acousto-optic diffraction

实验研究了多级声光衍射条件下的最佳声光相互作用长度与声波和光波之间的定量关系。测量结果表明最佳声光相互作用长度与声频紧密相关而几乎与入射光波长及强度无关。实验结果发现当声频低时,相互作用长度短,声频在9 MHz左右,相互作用长度约为8 mm,当声频降低为6 MHz左右时,相互作用长度约为4 mm。设计了以纯水为介质的声光Q开关器件,在超声频率9 MHz,声功率3.4 W的条件下实现了约98%的总衍射效率。

The experimental investigation on the interaction length for getting the optimum diffraction of the multi-order acousto-optic diffraction is introduced. Measurement resuhs show that best acousto-optic interaction length is closely related to audio frequency, and it is not almost relate to the wavelength and power of the light. When audio frequency is lower, the interaction length became shorter. As audio frequency is about 9MHz, the interaction length is about 8mm, it shrinks to about 4mm at 6MHz of audio frequency. An acousto-optic Q-switch apparatus working with pure water is designed, and a total diffractive efficiency of about 98 % is obtained under the condition of acoustic frequency at 9MHz and acoustic power at 3.4W.