Optical properties and application potential of a hybrid cavity compound grating structure

Abstract

In this paper, we propose a new type of metal-insulator-metal (MIM) hybrid cavity compound grating micro-structure array, which can achieve dual narrowband super-absorption in the near-infrared window. The thin plasmonic microstructure effectively modulates coupling and hybridization effects between surface plasmon polaritons of different transmission resonance cavities to form designable dual narrowband resonance states to achieve near-infrared operation proving manipulation of the optical characteristics in the near-infrared light field. Furthermore, we conduct an in-depth theoretical exploration of the structure's unique properties, such as its high-quality factor, low noise, super-absorption, precise control, and the physical mechanism of its excellent performance in ambient refractive index sensing and detection. This study provides developmental insights for the miniaturization, easy modulation, and multi-function development of surface plasmon superabsorbers while broadening their application in near-infrared environment refractive index detection. The proposed microstructure is also suitable for integration with optical elements.

Trends of Biosensing: Plasmonics through Miniaturization and Quantum Sensing

“…This duality of behavior has been achieved by systems featuring an antenna mode and a cavity mode; the cavity realizes a high efficiency in photon collection by holding the radiation and enhancing the light/matter interaction, while the antenna improves the directionality of the emission, by coupling the system to the free space [134] . The hybridization of the two modes has the ability to push the detection limit down to a THz regime and to induce the matching of two impedances, resulting in a reduction of the lossy character of the metal and linewidth [135] , with a significant impact on the radiative behavior as well [136] . As an example, Figure 7a shows a waveguide (panel i) fabricated using a combination of bottom-up/top-down processes; the device is strain tuned and was demonstrated when integrated with a quantum emitter and a planar integrated optical resonator consisting of a silicon nitride ring resonator fabricated on a piezoelectric substrate (panel ii).…”