A review of acoustic Luneburg lens: Physics and applications

摘要

Acoustic Luneburg lens (ALL) is a spherically/circularly symmetric gradient refractive index lens, whose index varies smoothly from the outer surface to the centre. The variation of the index can be achieved via the changing of filling ratio of unit cells or varying the structural thickness based on specific governing equations. The fundamental principles were used to explain the acoustic wave propagation in such inhomogeneous media, and to design different types of ALL. This review will describe the fundamental theories of ALL, introduce different types of ALL, and discuss extensive applications of ALL, which have been exploited for the manipulation and control of both acoustic and elastic waves.

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