Multi-channel coherent perfect absorbers

¹ College of Physics, Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University - Suzhou 215006, China
² Division of Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST) - Thuwal 23955-6900, Saudi Arabia

^(a) Ying.Wu@kaust.edu.sa
^(b) laiyun@suda.edu.cn

Received: 18 March 2016
Accepted: 2 May 2016

Abstract

The absorption efficiency of a coherent perfect absorber usually depends on the phase coherence of the incident waves on the surfaces. Here, we present a scheme to create a multi-channel coherent perfect absorber in which the constraint of phase coherence is loosened. The scheme has a multi-layer structure such that incident waves in different channels with different angular momenta can be simultaneously and perfectly absorbed. This absorber is robust in achieving high absorption efficiency even if the incident waves become “incoherent” and possess “random” wave fronts. Our work demonstrates a unique approach to designing highly efficient metamaterial absorbers.