A Novel Ultra-Low Loss Rectangle-Based Porous-Core PCF for Efficient THz Waveguidance: Design and Numerical Analysis

Analytical approach for modeling and simulation of photonic crystal fiber based on low effective material loss

COMSOL Multiphysics simulation software has been used to create a hexagonal photonic crystal fiber (H-PCF) with hexagonal cladding and a rotating hexa elliptical shape core. The hexagonal photonic crystal fiber (H-PCF) fiber is built on five layers of circular air holes, and it is suitable for telecommunication applications especially optical fiber communication in the terahertz (THz) frequency range. The hexagonal photonic crystal fiber (H-PCF) is designed to have an ultra-low effective material loss (EML), a higher core power fraction, a bigger effective area, and reduced confinement loss. The smallest effective material loss from the proposed hexagonal photonic crystal fiber (H-PCF) is 0.00689 cm−1, with a better core power fraction of 82%, less confinement loss of 3.45 × 10–14 cm−1 and a better effective area of 3.65 × 10–4 m2 is achieved at one terahertz (THz) waveguide region. Furthermore, using the features of the V-Parameter, our developed hexagonal photonic crystal fiber (H-PCF) fiber reveals an optical waveguide with one mode throughout a frequency range of terahertz (THz) wave area. So, it has been said that our hexagonal photonic crystal fiber (H-PCF) structure will be highly beneficial for optical fiber communications applications in the THz frequency range.

Tunable liquid crystal core refractive index sensor based on surface plasmon resonance in gold nanofilm coated photonic crystal fiber

We propose, to the best of our knowledge, a novel kind of tunable liquid crystal core refractive index (RI) sensor based on photonic crystal fiber (PCF) covered with a nanoring gold film. The finite element method is used to discuss and analyze the sensing performance of the RI sensor. Gold is used as the excitation material for surface plasmon resonance, and a gold nanoring is embedded around the first cladding of the PCF. The liquid analytes penetrate the outermost layer of the cladding, and the central hole is filled with liquid crystal E7. Complete coupling and incomplete coupling are excited as the analyte RI increases, and the resonance strength of complete coupling is stronger than that of incomplete coupling. It can be proved by calculation that at different wavelengths, resonant coupling of fifth-order and sixth-order surface plasmon polaritons is obtained. The RI of liquid analytes ranges from 1.405 to 1.445. The diameters of the liquid crystal cores are 0.2, 0.4, 0.6, and 0.8 µm; their average sensitivities are 10700, 10566, 10167, and 9166 nm/RIU; and the linear fitting constants are 0.98025, 0.97387, 0.96597, and 0.95507, respectively. In short, the RI sensor has the advantages of tunability, wide range, and high sensitivity, and is expected to be applied in various fields.