The aim of this paper is to overcome the acoustic diffraction limit to achieve finer lateral resolution in and out of focus regions. For this purpose, a well-known structured-illumination method is used to increase the acoustic spatial bandwidth to improve the lateral resolution of the system. The illuminated optical beam is shaped by a digital micromirror device (DMD) to form sinusoidal patterns force to shift the object spatial spectrum. The shifted spectrum passes high spatial frequency components through the finite bandwidth of the system. Here, the phase compounding method is modified in comparison with [1] to increase the lateral resolution improvement from 2 to 5 times. To achieve this goal, adding the spatial frequency component of the second order to the fundamental component by considering phase shifts of 0,45,90 and 180 degree and orientations of 0,45,90, and 135 degree. The experimental results validate the performance of the system.
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