Optical properties of a double-cavity system coupled to a waveguide in photonic crystals

Abstract

The optical properties of a pair of directly interacting cavities, side-coupled to a waveguide, are investigated analytically by the coupled-mode theory. Due to the indirect coupling via waveguide, the resonance split can be controlled through the involved direct coupling coefficients and the indirect coupling phase shift. As a result, a variety of complete transmissions, two different types of one-peak reflectivity profiles, and two-peak reflectivity profiles can be obtained. All the predictions of the resonator-waveguide coupling systems obtained theoretically are validated numerically by the finite-difference time-domain method in photonic crystals.

Strong Oxide‐Support Interaction over IrO2/V2O5 for Efficient pH‐Universal Water Splitting

“…Compared to IrO 2 analog, however, the (110) characteristic reflection in the IrO 2 /V 2 O 5 sample broadens and shifts to a lower degree at 2 θ = 27.6°, indicating an lattice expansion feature of IrO 2 induced by the known effects of strain on both the position and width of diffraction peaks. [ 42,43 ] Moreover, high‐resolution transmission electron microscope (HRTEM) image and corresponding line‐scan profile (Figure 1d and Figures S6 and S7, Supporting Information) demonstrate that IrO 2 nanoclusters (NCs) with mean size of ≈1 nm are uniformly embedded on porous skeleton of V 2 O 5 . Scanning transmission electron microscopy (STEM) and corresponding elemental mapping images (Figure S8, Supporting Information) elucidate that Ir, V, and O elements are uniformly distributed over the region, and Ir loading is 20.8 wt%, which is consistent with the result of inductively coupled plasma‐optical emission spectrometry (ICP‐OES，19.7 wt%) (Table S1, Supporting Information).…”