Temperature Tunable Multiple Ultraviolet to Near-Infrared Perfect Absorption as Highly Sensitive Metamaterial Biosensor
Tian Guo, Ying Zhong, Zhendong Yan, Xingting Pu, Wei Du, Fan Gao, Chaojun Tang
Abstract
Realizing tunable multiband perfect absorption from ultraviolet (UV) to near-infrared (IR) range in nanophotonics and metamaterials is extremely significant for solar energy harvesting and optical sensors. Here, five narrowband and broadband perfect absorbers (PA) are simultaneously achieved in a simple 3-D metamaterial consisting of aluminum (Al) standing U-shaped split-ring resonators (SUSRRs) on SiO2/Al layer, which stems from the plasmonic hybridization between three high-order surface plasmon polarization (SPPs) and multiple localized surface plasmon (LSPs) localized both within the individual SUSRR as well as within the dielectric layer underneath the SUSRR. These penta-band perfect absorption peaks can be tuned by varying the temperature of the sealed ethanol with a temperature tuning performance of 0.331 nm/°C. Due to the two narrow perfect absorption at 473 and 157 nm being sensitive to the surroundings, our proposed Al SUSRR array as a high-sensitivity biosensor displays the ultra-large figure of merit (FoM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\ast} $ </tex-math></inline-formula> ) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.0\times104$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.55\times104$ </tex-math></inline-formula> , which could be applied to gas sensing and the detection of the sub-nanometer thickness of analyte film.