Electrically Tunable Defect-Mode Wavelengths in a Liquid-Crystal-in-Cavity Hybrid Structure in the Near-Infrared Range.

This work proposes a novel approach to developing a core component for a near-infrared (NIR) spectrometer with wavelength tunability, which is based on a liquid crystal (LC)-in-cavity structure as a hybrid photonic crystal (PC). By electrically altering the tilt angle of the LC molecules under applied voltage, the proposed PC/LC photonic structure consisting of an LC layer sandwiched between two multilayer films generates transmitted photons at specific wavelengths as defect modes within the photonic bandgap (PBG). The relationship between the number of defect-mode peaks and the cell thickness is investigated using a simulated approach based on the 4 × 4 Berreman numerical method.

Investigation of Antireflection Nb₂O₅ Thin Films by the Sputtering Method under Different Deposition Parameters.

In this study, Nb₂O₅ ceramic was used as the target to deposit the Nb₂O₅ thin films on glass substrates with the radio frequency (RF) magnetron sputtering method. Different deposition temperatures and O₂ ratios were used as parameters to investigate the optical properties of Nb₂O₅ thin films. The deposition parameters were a pressure of 5 × 10 Torr, a deposition power of 100 W, a deposition time of 30 min, an O₂ ratio (O₂/(O₂ + Ar), in sccm) of 10% and 20%, and deposition temperatures of room temperature (RT), 200, 300 and 400 °C, respectively.