Elliptical defected core photonic crystal fiber with high birefringence and negative flattened dispersion

Numerical investigation of high birefringence and nonlinearity tellurite glass photonic crystal fiber with microstructured core

In this paper, a novel photonic crystal fiber (PCF) based on tellurite glass with high birefringence and high nonlinearity is designed. Six small air holes arranged nearly rectangularly are added in the fiber core to form the near-elliptic core. By using the finite-element method with the help of COMSOL Multiphysics software, we investigate and simulate the birefringence, effective mode area, nonlinear coefficient, and the dispersion characteristics. Simulation results show that by optimizing the structure parameters of the core, at the wavelength of 1.55 µm, the birefringence is up to ${5.05} \times {{1}}{{{0}}^{- 2}}$; the nonlinear coefficient can reach a maximum of ${{1896}}\;{{\rm{W}}^{- 1}}\;{\rm{k}}{{\rm{m}}^{- 1}}$; moreover, the zero dispersion points can be obtained around the wavelength 1.55 µm. The proposed structure is easy to fabricate. The advantage of the proposed PCF has potential applications in polarization control, communication systems, and supercontinuum generation.

Numerical analysis of photonic crystal fiber of ultra-high birefringence and high nonlinearity

A numerical analysis of a hexagonal PCF structure with four circular air hole rings around the core has been presented in this paper. By utilizing a full vectorial finite element method with perfectly matched layers, propagation properties such as birefringence, chromatic dispersion and confinement losses are numericaly evaluated for the proposed PCF structure. Specifically, birefringence of 2.018 × 10-2, nonlinear coefficients of 40.682 W-1 km-1, negative chromatic dispersion of - 47.72 ps/km.nm at 1.55 µm and - 21 to - 105 ps/km.nm at the telecommunication band of C-U have been reported.

All-circular hole microstructured fiber with high birefringence and low confinement loss

An air-silica microstructure optical fiber of ultrahigh birefringence of the order ∼10^-2 and low confinement loss is proposed. The birefringence is achieved by axial anisotropy introduced in the fiber geometry by the preferred arrangement of circular air holes of different sizes in the cladding structure. Vital properties of the microstructure fiber, e.g., birefringence, confinement loss, dispersion, and walk-off, have been studied by employing numerical solutions through the finite element method. These findings should be useful for the fabrication of the proposed microstructure optical fiber.

Dodecagonal photonic quasi-crystal fiber with high birefringence

A photonic quasi-crystal fiber (PQF) with high birefringence is proposed. A dodecagonal Stampfli quasi-periodic lattice of air holes constitutes the cladding of the PQF. The PQF maintains the properties of high birefringence and single-mode operation regime in a wide wavelength range from 1.2 to 2.0 μm by optimizing the size of the air holes around the core of the PQF. A birefringence with 3.86×10^-2 can be obtained at 1.31 and 1.55 μm optical telecommunication windows. The birefringence is of the order of 10^-2, which is two orders of magnitude larger than that of the conventional polarization-maintaining fibers and hardly affected by the incident wavelength. The proposed PQF also maintains a high nonlinear coefficient and low confinement loss. Our structure and simulation results are expected to provide a valuable reference and basic data to relative fabrication and experiments.

Polarization-maintaining low-loss porous-core spiral photonic crystal fiber for terahertz wave guidance

A polarization-maintaining porous-core spiral photonic crystal fiber is proposed for efficient transmission of polarization-maintaining terahertz (THz) waves. The finite element method with perfectly matched layer boundary conditions is used to characterize the guiding properties. We demonstrate that by creating artificial asymmetry in the porous core, an ultrahigh birefringence of 0.0483 can be obtained at the operating frequency of 1.0 THz. Moreover, a low effective material loss of 0.085  cm^-1 and very small confinement loss of 1.91×10^-3  dB/cm are achieved for the y-polarization mode with optimal design parameters. This article also focuses on some crucial design parameters such as power fraction, bending loss, and dispersion for usability in the THz regime.

PCF Based Sensor with High Sensitivity, High Birefringence and Low Confinement Losses for Liquid Analyte Sensing Applications

In this paper, we report a design of high sensitivity Photonic Crystal Fiber (PCF) sensor with high birefringence and low confinement losses for liquid analyte sensing applications. The proposed PCF structures are designed with supplementary elliptical air holes in the core region vertically-shaped V-PCF and horizontally-shaped H-PCF. The full vectorial Finite Element Method (FEM) simulations performed to examine the sensitivity, the confinement losses, the effective refractive index and the modal birefringence features of the proposed elliptical air hole PCF structures. We show that the proposed PCF structures exhibit high relative sensitivity, high birefringence and low confinement losses simultaneously for various analytes.

Design of a pentagonal photonic crystal fiber with high birefringence and large flattened negative dispersion

Novel pentagonal photonic crystal fiber with high birefringence, large flattened negative dispersion, and high nonlinearity is proposed. The dispersion and birefringence properties of this structure are simulated and analyzed numerically based on the full vector finite element method (FEM). Numerical results indicate that the fiber obtains a large average dispersion of -611.9  ps/nm/km over 1,460-1,625 nm and -474  ps/nm/km over 1425-1675 nm wavelength bands for two kinds of optimized designs, respectively. In addition, the proposed PCF shows a high birefringence of 1.67×10^-2 and 1.75×10^-2 at the operating wavelength of 1550 nm. Moreover, the influence of the possible variation in the parameters during the fabrication process on the dispersion and birefringence properties is studied. The proposed PCF would have important applications in polarization maintaining transmission systems, residual dispersion compensation, supercontinuum generation, and the design of widely tunable wavelength converters based on four-wave mixing.

High birefringence photonic crystal fiber with high nonlinearity and low confinement loss

A particular photonic crystal fiber (PCF) designed with all circle air holes is proposed. Its characteristics are studied by full-vector finite element method (FEM) with anisotropic perfectly matched layer (PML). The simulation results indicated that the proposed PCF can realize high birefringence (up to 10(-2)), high nonlinearity (50W(-1)·km(-1) and 68W(-1)·km(-1) in X and Y polarizations respectively) and low confinement loss (less than 10(-3)dB/km at 1.55um wavelength).

High-birefringence, low-loss porous fiber for single-mode terahertz-wave guidance

A new kind of polymer porous fiber with elliptical air-holes is designed for obtaining high birefringence in the terahertz (THz) frequency range in this paper. Using the finite element method, the properties of this kind of fiber are simulated in detail including the single-mode propagation condition, the birefringence, and the loss. Theoretical results indicate that the single-mode THz wave in the frequency range from 0.73 to 1.22 THz can be guided in the fiber; the birefringence can be enhanced by rotating the major axis of the elliptical air-hole and there exists an optimal rotating angle at 30°. At this optimal angle a birefringence as high as 0.0445 can be obtained in a wide frequency range. Low-loss THz guidance can be achieved owing to the effective reduction of the material absorption in such a porous fiber. This research is useful for polarization-maintaining THz-wave guidance.