Near-infrared dual-wavelength plasmonic switching and digital metasurface unveiled by plasmonic Fano resonance

Abstract

Plasmonic Fano resonance (FR) that contributes to multitudinous potential applications in subwavelength nanostructures can facilitate the realization of tunable wavelength selectivity for controlling light–matter interactions in metasurfaces. However, the plasmonic FR can be generated in metasurfaces with simple or complex geometries, and few of them can support flexible amplitude modulation and multiwavelength information transfer and processing. Here, we study the near-infrared plasmonic FR in a hybrid metasurface composed of concentrically hybridized parabolic-hole and circular-ring-aperture unit cells, which can induce polarization-dependent dual-wavelength passive plasmonic switching (PPS) and digital metasurface (DM). It is shown that the designable plasmonic FR can be realized by changing the geometric configurations of the unit cells. In particular, owing to the polarization-dependent characteristic of FR, it is possible to fulfill a compact dual-wavelength PPS with high ON/OFF ratios in the related optical communication bands. Moreover, such PPS that manipulates the amplitude response of the transmitted spectrum is an efficient way to reveal a 1-bit DM, which can also be rationally extended to a 2-bit DM or more. Our results suggest a pathway for studying polarization-dependent PPS and programmable metasurface devices, yielding possibilities for subwavelength nanostructures in optical communication and information processing.

Plasmonic Sensing and Switches Enriched by Tailorable Multiple Fano Resonances in Rotational Misalignment Metasurfaces

“…For the central wavelengths of 1199 and 1977 , as shown in Figure 6 a, their transmittance spectra can be modulated by regulating the polarization direction of the incident light, accompanied directly with the presence/absence of the in-plane mirror symmetry. The ON/OFF ratio ( ) and modulation depth ( ) can be written as [ 18 , 52 ], where and depict the “ON” and “OFF” states at the related wavelengths, respectively.…”

“…Plasmonic Fano resonance (FR) generated by the interaction between the broad superradiant and narrow subradiant modes [ 11 , 12 ] results in strong field enhancement with a sharp asymmetric spectral profile that is utile for FR-based devices [ 13 ]. As in the following, the plasmonic FR promises new avenues for ultrasensitive sensing [ 14 , 15 , 16 ], optical switches [ 17 ], and digital metasurfaces [ 18 ]. Compared with a single FR, multiple FRs are more sensitive to structural parameters and the surrounding environment, and have also attracted significant attention due to their further improvement and expansion of functionalities in optical metasurfaces [ 19 , 20 ].…”

Slow-light effects based on the tunable Fano resonance in a Tamm state coupled graphene surface plasmon system

“…5,6 Generally, the Fano resonance arises from the destructive and constructive interference between a broad continuum resonance and a narrow discrete resonance. The high dispersion of the Fano resonance endows it with potential application in switching, 7 slow-light devices, 8,9 lasing, 10,11 and sensors. 12,13 Much work on Fano resonance so far has focused on the plasmonic resonances of noble metals, [14][15][16] and the high ohmic loss of metal-based structures will generate the Fano resonance with a low-quality factor.…”

Polarization-Resolved Position-Sensitive Self-Powered Binary Photodetection in Multilayer Janus CrSBr

“…On the other hand, polarization-sensitive PDs are demanding in state-of-the-art technology including quantum computing, efficient three-dimensional object detection in light detection and ranging (LiDAR) devices, high-density optical signal processing, navigation, and high-contrast polarizers. , Detection of optical polarization utilizing optically anisotropic materials has attracted increasing research interest in recent years. Low-charge symmetry crystals such as layered van der Waals materials including black phosphorus, GaTe, GeS, SnS, SnSe, ReSe 2 , ReS 2 , and GeAs 2 , exhibit in-plane optical anisotropy and birefringence making them promising materials for the detection of optical polarization. − However, poor air stability and oriented growth are among the several shortcomings that limit their performance and practicality. , The investigation of stable low-symmetry 2D materials and their polarization-selective light–matter interaction and the interplay between their layer thickness, structural, and optical anisotropy are still in their early stage . Recently discovered Janus materials provide additional freedom to introduce an optically anisotropic response in monolayer 2D materials.…”