Enhanced quasi-BIC refractive index sensing based on controlling the Fermi energy of Dirac semimetal metasurface

An active controllable wide-angle and ultra-wideband terahertz absorber/reflector based on VO2 metamaterial

“…This is because the proposed device was highly symmetrical, indicating that the absorption was independent of polarization for the normal incident. 18–21 In addition, the absorption bandwidth (more than 90% absorption rate) ranged from 4.0 to 10.0 THz, reaching 6.0 THz, and the average absorption rate was calculated to be as high as 97.2%. The absorption bandwidth (>90%) considerably exceeded that of other absorbers, 12–17 providing ideas for the field of terahertz absorption.…”

Coexistence of giant Goos–Hänchen shift and high reflectance in Dirac semimetal based multilayered structure

“…The dielectric constant ( ε ) of the BDS can be expressed as ε = ε b + iσ /( ε 0 ω ), where ε 0 is the vacuum dielectric constant and ε b = 12 is the effective background dielectric constant. 47,48…”

“…The dielectric constant (e) of the BDS can be expressed as e = e b + is/(e 0 o), where e 0 is the vacuum dielectric constant and e b = 12 is the effective background dielectric constant. 47,48 To calculate the GH shift of the reflected wave from the surface of the multilayered structure, we first need to calculate its reflectance coefficient. Therefore, we choose to use the transfer matrix method (TMM) to calculate the reflectance coefficient of our designed multilayered structure.…”

Phase Interrogation Sensor Based on All-Dielectric BIC Metasurface

“…Owing to the low loss and high Q factor, refractive index sensors based on all-dielectric BIC metasurface also possess good biocompatibility, compatibility with CMOS process, and the ability to integrate with microfluidic technology. Therefore, numerous studies have been reported in recent years on enhanced refractive index sensors based on BIC. − These studies mainly focus on the design, construction, or optimization of a high- Q BIC resonant structure to enhance the sensing performance, for example, the crescent BIC metasurface, nanogap-enhanced BIC structures, dielectric metal hybrid BIC metasurface, and zigzag elliptical structure arrays, among others. However, the refractive index sensitivity achieved via these enhanced designs is generally in the range of tens to hundreds of nm/RIU, which is nearly 2 orders of magnitude lower than that of refractive index sensors based on the metal substrate, such as plasmonic sensors , and hyperbolic metamaterial sensors, significantly limiting the application of BIC and the entire all-dielectric metasurface in ultrahigh sensitive refractive index sensing.…”

“…However, the refractive index sensitivity achieved via these enhanced designs is generally in the range of tens to hundreds of nm/RIU, which is nearly 2 orders of magnitude lower than that of refractive index sensors based on the metal substrate, such as plasmonic sensors , and hyperbolic metamaterial sensors, significantly limiting the application of BIC and the entire all-dielectric metasurface in ultrahigh sensitive refractive index sensing. Even if some studies may achieve figures of merit (FoM) comparable to the metal-based substrate, the low sensitivity results in a refractive index resolution of approximately 10 –4 –10 –5 RIU, , which is much lower than that of metal-based refractive index sensors. These numerous limitations keep the all-dielectric BIC metasurface far from the realm of ultrahigh sensitivity sensing.…”