https://doi.org/10.1140/epjd/s10053-022-00447-x
Regular Article – Optical Phenomena and Photonics
Enhanced chirality of TDBC based on gap modes of surface plasmons in metal-air hole array structure
1
School of Electronic Engineering, Beijing University of Posts and Telecommunications, No. 10 Xitucheng Road, 100876, Beijing, China
2
School of Science, Beijing University of Posts and Telecommunications, No. 10 Xitucheng Road, 100876, Beijing, China
3
International School, Beijing University of Posts and Telecommunications, No. 10 Xitucheng Road, 100876, Beijing, China
Received:
20
March
2022
Accepted:
24
June
2022
Published online:
27
July
2022
We propose a structure to enhance the chirality of chiral molecular J-aggregates (TDBCs) by surface plasmons. TDBC layer is sandwiched between an air hole array in a silver film and a silver substrate. Finite difference time domain method is used to simulate our proposed structures. The results show that the chirality of our proposed structure is as 240 times as the one of only TDBCs. Air hole forms a low-quality-factor Fabry–Perot (FP) cavity, and these FP cavities enhance the electric field. With the help of FP cavities, the coupling between electric fields and TDBCs is enhanced, and the chirality is amplified. By tuning the parameters of the structure, there is a suit of parameters to make the maximum value of the circular dichroism (CD) spectrum the largest. This shows the competition between the dissipation induced by FP cavities and the coupling between FP cavities and TDBCs. This competition also presents in the changing the thickness of TDBCs. There is an optimal thickness of TDBCs to make the maximum value largest. Our structure can enhance the chirality of TDBCs in a large wavelength range of visible light, providing a new and possible way to enhance the chirality of TDBCs.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2022
