Phase and amplitude modulation with acoustic holograms
Phase and amplitude modulation with acoustic holograms
复制标题
DOI：
10.1063/1.5110673
复制
发表时间：
2019-07-29
影响因子：
4
通讯作者：
Brown, Michael D.
中科院分区：
文献类型：
--
作者：
Brown, Michael D.
声全息图是一种低成本的产生三维任意衍射极限压力分布的方法。然而，目前，使用这种方法创建复数场受到这些全息图不能独立地调制入射波的相位和幅度的限制。在这项工作中，证明了这一限制可以通过使用两个位相全息图，设计了迭代傅里叶变换算法，以形成一个预定义的表面上的反向传播的目标图案的位相共轭。设计了一个实验测试用例，用来产生幅度和相位均匀的字母UCL，以验证该技术的可行性。对该样品的现场测量表明，这种方法可以实现声场的相位和幅度的调制。
Acoustic holograms are a low cost method for generating arbitrary diffraction limited pressure distributions in 3 dimensions. However, at present, the creation of complex fields using this approach is limited by the inability of these holograms to independently modulate both the phase and amplitude of an incident wave. In this work, it is shown that this limitation can be circumvented by using two phase holograms, designed using an iterative Fourier transform algorithm, to form the phase conjugate of a back-propagated target pattern over a predefined surface. An experimental test-case, designed to generate the letters UCL with the uniform amplitude and phase, is prepared to demonstrate the feasibility of this technique. Field measurements from this sample show that the modulation of both the phase and amplitude of the acoustic field can be achieved with this approach.