Directional control of absorptivity with quasi-localized guided modes

Abstract

We present a guided mode resonance grating that exhibits high-Q resonances with highly selective directional absorption around 3.7 μm. The grating is designed to create slow guided mode resonances with near-flat dispersion relation. Weakly coupled resonators enable such resonances with small dispersion characteristics. We study the dynamic control of directional absorption using the design presented. We show that weaker dispersion of resonance frequency allows a strong sensitivity concerning the directionality of resonance. Our results indicate that the directionality of absorption can be tuned from normal incidence (0°) to approximately 35° upon small index perturbation. The design presents a pathway toward tunable directional absorption and emission.

Theoretical investigation of the optical and electronic properties of surface engineered V 2 N MXene

“…For Ti 2 CO 2 , the absorption maxima at 3.2 eV energy was reported in [45] with an absorption coefficient of 3.6 × 10 5 . In another research [23], in case of oxygen and fluorine adsorbed V 3 C 2 , absorption coefficient of 3.8 × 10 5 and 3.3 × 10 5 is reported in the visible region, respectively. In the present study, the observed absorption coefficient for O, S, Se and Te adsorbed V 2 N MXene in the visible region is 1.75 × 10 5 , 3.48 × 10 5 , 3.80 × 10 5 and 4.20 × 10 5 , respectively (see table 2), which is higher than the previously reported studies.…”

“…New 2D transition metal carbides and nitrides called 'MXenes' have shown promise in several areas, including ion batteries [12][13][14][15], electromagnetic interference shielding [16][17][18], conductive thin films [19,20], photonics [21][22][23][24], and photothermal therapy [25,26]. The reason for their popularity in such applications is their metallic composition, broad range of optical absorption and tunable surface chemistry.…”