超声驻波波面的激光相关成像

本文利用傅氏光学概念分析激光通过声驻波后的远场光场,不但被分解成空间频谱,而且在空间频谱中又有时间频谱。以此为依据,分析了超声驻波成稳定像的原理和过程:通过时间互相关过程,得出不同空间频谱中同时间频率光的非零相关值;再由不同时间频率的非相干光进行强度线性叠加,最后形成超声驻波波面的稳定像。从而澄清了声驻波成像中的一些理论上的混淆,找到了成像的新途径,实验上也得到了证实。

Laser correlation imaging of UHF acoustic standing wavefront

On the basis of the Fourier optics, we've analysed the optical far-field of a laser beam passing through the UHF acoustic standing waves and found that there is temperal spectrum in the spatial spectrum on the far-field plane besides the spatial spectrum. In accordance with the above results we've developed an imaging principle of UHF acoustic standing wavefronts: by temporal crosscorrelation, the non-zero Value of correlation of the same temporal frequencies in the different spatial frequencies is obtained; then by intensity linear superposition of incoherent light of the different temporal frequencies, a stable visible image of UHF acoustic standing wavefronts is obtained. Therefore we have not only clarified the confusion of the theory but also developed a new method for imaging the UHF acoustic st anding wavefronts. And the results have been proved experimentally.