A high-precision reconstructing technique for a high-frequency acoustic field based on the angular spectrum method

摘要

To apply ultrasonic radiation force in precise manipulation for micro-components, a reconstruction technique for low-frequency sound field based on angular spectrum method (ASM) was adopted in the reconstruction for high-frequency sound field, and a high-precision reconstructing technique for high-frequency sound field was developed. First, the principle of reconstructing the sound field by ASM and four key factors on reconstruction precision were analysed. Second, the marginal Gibbs phenomenon and aperture replication effect were decreased by optimizing of the sampling interval and holographical aperture, and the signal-to-noise ratio (SNR) was increased by using the tapered filter to pretreat the signal data in wave number space. Then, the ill-posedness in reverse problem was eliminated by using a new kind of k-space filter to refine the transfer function. Finally, the reconstruction experiment of 1.75 MHz ultrasonic field was conducted by using the three-dimensional precise scanning system and needle-type hydrophone, and the experimental results validate the feasibility and efficiency of the method proposed in this study.