Splitting of self-collimated beams in two-dimensional sonic crystals

TL;DR

This paper presents a practical method to split self-collimated acoustic beams in two-dimensional sonic crystals using line-defects, achieving high efficiency and wide-angle operation, with potential for multi-way splitting.

Contribution

It introduces a novel line-defect based scheme for beam splitting in sonic crystals, enabling adjustable power ratios and multi-way splitting with high efficiency.

Findings

Achieves over 90% splitting efficiency for Gaussian beams

Demonstrates wide-angle and broadband operation

Realizes splitting for point sources with subwavelength imaging

Abstract

An easy-to-implement scheme to split self-collimated acoustic beams in sonic crystals (SCs) is proposed by introducing line-defects into SCs, by which an incoming self-collimated beam can be split into a 90 degree-bended one and a transmitted one with an arbitrary power ratio by adjusting the value of defect size. An all-angle and wide-band splitting instrument is demonstrated with nearly perfect efficiency (more than 90%) for Gaussian beams at a wide range of incident angles. Splitting effect for a point source as input is also realized, in which two subwavelength images of the source, i.e., a bended one and a transmitted one, are formed by our designed splitting structure. Finally, the proposed one-to-two splitting scheme is generalized to one-to-N (N>2) cases by inserting more rows of line defects into the SC.