Hybrid FEA & Fresnel diffraction simulation of 3D GHz Acoustic Meta-lens

Ultrasonic lenses are not only useful for implementing Fourier computing using ultrasonics, but they can also be used in acoustic imaging. Conventional simulation of ultrasonic meta-lenses requires computationally intensive finite element analysis (FEA). To the best of our knowledge, we report for the first time a computationally inexpensive hybrid method of combining FEA with a Fresnel diffraction solver to enable the simulation of a 237 µm large radius 3D acoustic meta-lens with focal length of 4 mm, operating at 1.7 GHz. The focusing efficiency at the image plane 4 mm away from our meta-lens was found to be 75.1%.