Ultra-narrowband resonant light absorber for high-performance thermal-optical modulators

Abstract

Herein, a tunable thermal-optical ultra-narrowband grating absorber is realized. Four ultra-sharp absorption peaks in the infrared region are achieved with the absorption efficiency of 19.89%, 98.41%, 99.14%, and 99.99% at 1144.34 nm, 1190.92 nm, 1268.58 nm, and 1358.70 nm, respectively. Benefiting from an extremely narrow bandwidth (0.27 nm), a maximum Q-factor over 4400 is obtained for the absorber. Moreover, the spectral response can be artificially tuned by controlling the temperature via the strong thermo-optic effect of silicon resonator. The high absorption contrast ratio of 23 dB is demonstrated by only increasing the temperature by 10 °C, showing an order of magnitude better than that of the previously demonstrated performance in the infrared image contrast manipulation. Also, the absorption intensity can be precisely regulated via tuning the polarization state of incident light. Strong tunability extending to temperature and polarization states makes this metasurface promising for applications in a high-performance switch, notch filter, modulator, etc.

Multi-function sensing applications based on high Q-factor multi-Fano resonances in an all-dielectric metastructure

“…Due to significant near-field enhancement and narrow spectral characteristics, high Q-factor Fano resonance is extensively applied in high-performance sensors [ 25 , 26 ]. Liao et al proposed a temperature sensor based on a grating-like metastructure, which achieved the maximum Q-factor of 4400 and the maximum sensitivity of 68.7 pm/°C [ 27 ]. Yu et al proposed a refractive index sensor based on an asymmetric semi-circular metastructure, which achieved the maximum Q-factor of 2617, the sensitivity of 300 nm/RIU, and the FOM of 440 RIU -1 [ 28 ].…”

Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF4 particles

“…Some of these methods rely on macroscopic heat sources to kill the diseased tissue. Photothermal therapy using nano/ microparticles has been introduced as yet another technique to treat patients [6][7][8][9][10]. In this regard, photothermal therapy by employing upconverting particles (UCPs) has gained recent research interest since these particles themselves emerge as multi-modal probes to their environment [11,12].…”

Adaptive gold/vanadium dioxide periodic arrays for infrared optical modulation

“…Nature, size, shape, and shape dispersions of the objects constitute a key point to adjust the band of the LSPR [29,30]. A narrowband resonant mode could be more suitable for improving application performances [31,32].…”