Tellurite suboxide based near-infrared reflector and filter

TeO1.4/SiO2 one-dimensional photonic crystals (1D PCs) were prepared using radio frequency (RF) magnetron sputtering to fabricate a reflector and a filter with photonic band gaps (PBGs) in the near infrared (NIR) region. Stoichiometry and phase state of the TeOx thin film were characterized via X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD), respectively. The microstructural and optical characteristics of the 1D PCs were evaluated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and ultraviolet visible near-infrared spectrophotometer (UV-VIS-NIR). The experimental reflectance spectra were consistent with the theoretical results simulated using the transfer matrix method (TMM). For the reflector, a PBG of 1273-1676 nm (Δλ = 403 nm) was achieved in the NIR region. For the filter, the introduction of a defect layer in the 1D PC led to a resonant peak at the central wavelength of 1461 nm within the PBG of 1250-1733 nm (Δλ = 483 nm). The effects of the structural parameters, including the incident angle, the state of polarization and the thickness of the defect layer, were also theoretically analyzed.