Transparent and Ultra-lightweight Design for Ultra-Broadband Asymmetric Transmission of Airborne Sound
Jie Hu1,2**, Bin Liang1, Xiao-Jun Qiu3
1Key Laboratory of Modern Acoustics (MOE), Institute of Acoustics, Nanjing University, Nanjing 210023 2College of Information Science and Technology, Nanjing Forestry University, Nanjing 210000 3Centre for Audio, Acoustics and Vibration, Faculty of Engineering and IT, University of Technology Sydney, Sydney, Australia
Abstract：Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment. However, the previous mechanisms of asymmetric manipulation of airborne sound need to use elaborate heavyweight structures and only work in certain frequency ranges. We propose a mechanism for designing an ultra-lightweight and optically transparent structure with asymmetric transmission property for normally incident plane waves. Instead of fabricating solids into complicated artificial structures with limited bandwidth and heavy weight, we simply use xenon to fill a spatial region of asymmetric shape which allows the incident plane wave to pass along one direction while reflecting the reversed wave regardless of frequency. We demonstrate both analytically and numerically its effectiveness of producing highly-asymmetric transmission within an ultra-broad band. Our design offers new possibility for the design of one-way devices and may have far-reaching impact on various scenarios such as noise control.
2018, Vol. 35 
