Engineering heavily doped silicon for broadband absorber in the terahertz regime

Mingbo Pu,Chenggang Hu,Cheng Huang,Xiangang Luo,Min Wang,Zeyu Zhao,Yanqin Wang

doi:10.1364/oe.20.025513

Abstract

Highly efficient absorber is of particular importance in terahertz regime as naturally occurring materials with frequency-selective absorption in this frequency band is difficult to find. Here we present the design and characterization of a broadband terahertz absorber based on heavily Boron-doped silicon (0.7676 Ω cm) grating. It is numerically demonstrated by utilizing both the zero- and first order diffraction in the doped silicon wafer, relative absorption bandwidth larger than 100% can be achieved. Furthermore, the design can be easily extended to higher frequencies as the optical property of doped silicon is tunable through changing the doping concentration.

Highlights

Metamaterial (MM) perfect absorber has attracted much attention in recent years with potential applications in bolometers, solar cells and stealth technology [1,2,3,4,5]
We focus on the design of broadband absorber based on doped silicon, which has been considered as a new kind of metamaterial [18, 19] and used for tailoring the radiative properties [20]
This paper presents the design and characterization of a high efficient terahertz absorber based on a binary grating on heavily doped silicon

Summary

Introduction

Metamaterial (MM) perfect absorber has attracted much attention in recent years with potential applications in bolometers, solar cells and stealth technology [1,2,3,4,5]. This concept is of particular importance in terahertz frequencies due to the lack of accessible frequency-selective absorptive material [2, 4, 6, 7]. Compared with previous broadband absorbers, the structure proposed here is mechanically stable and much easier to fabricate

Principle and simulation

Conclusion