Abstract: The formation mechanism of ultrasonic grating is analyzed, analytical expression for the light intensity distribution of diffraction pattern of ultrasonic grating is derived, as well as a comparative study of diffraction pattern of ultrasonic grating and plane transmission grating is given by theoretical analysis and numerical simulation. The results show that the diffraction principal maximum satisfies the similar grating equation, but the intensity distribution of the pattern is different, capable of generating the phenomenon of missing order, but the law is different, and the ultrasonic grating is a dynamic grating, the frequency of every diffraction fringe is also different.

Key words: ultrasonic grating, plane transmission grating： diffraction fringes, numerical simulation