Design of Low-loss and Highly Birefringent Porous-Core Photonic Crystal Fiber and Its Application to Terahertz Polarization Beam Splitter

Abstract

We present the design of a porous-core PCF with elliptical holes in the core that achieved low loss, high birefringence, and flattened dispersion for guiding terahertz waves. The finite element method is used to study the properties of the designed waveguide in detail: effective material loss, birefringence, confinement losses, and dispersion. Simulation results show that the proposed structure exhibits simultaneously high modal birefringence of 1.32 × 10 −2 and a flattened dispersion over a broadband of 1.28 THz. Then, polarization splitters, based on both symmetric and asymmetric porous-core PCF structures, are designed and evaluated at 1 THz. We show that this kind of device exhibits a strong polarization-dependent coupling behavior. Numerical results show that the configuration based on dual-core waveguide with asymmetric cores can achieve a 10.9 cm long splitter with a broadband of 0.306 THz for x-polarization and 0.23 THz for y-polarization. Finally, this paper offers an effective method to design an ultrawideband polarization beam splitter to operate in the THz region, which might be relevant for future applications in technical areas, such as spectroscopy, sensing, and high-speed data transmission.

Numerical Analysis of Transversely Porous Core PCF with Square Airhole Cladding

“…Effective area basically defines the confinement area of fundamental mode in the core of fiber, and it can be numerically investigated using Eq. (10). From Fig.…”

Numerical Modeling of a Rectangular Hollow-Core Waveguide for the Detection of Fuel Adulteration in Terahertz Region

“…This commercial software makes the numerical analysis using full-vectorial finite element method (FEM). In addition, a rectangular perfectly matched layer (PML) boundary condition was introduced just at the outside of the cladding to absorb the electromagnetic signals propagating towards the core [37,47]. The PML is the most efficient absorption boundary condition, which helps to improve the numerical analysis and avoid possible sources of error [47,48].…”

“…The thickness of the PML is an important parameter due to its great impact on the simulation results. Therefore, we carry out the convergence test and found that proposed sensor provides the optimal results at a PML thickness above 10% of the total size of the sensor structure [37,49].…”

“…Besides, these waveguides had been proposed as sensors for different applications, like chemical sensing [31][32][33], biomedical sensing [34], cancer cell detection [35]. Based on the structure of the core, the PCFs can be broadly classified into three different categories: solid core PCF [36], porous core PCF [14,[37][38][39], and hollow-core PCF [26,40]. However, the hollow-core PCF is the best option for sensing applications because it provides the maximum area of interaction between the analyte and the radiation.…”

Tunable Mode Converter Device Based on Photonic Crystal Fiber with a Thermo-Responsive Liquid Crystal Core

“…The maximum element size in mesh is set five times smaller than the working wavelength. A cylindrical perfectly matched layer (PML) boundary condition, with a thickness of 1.55 µm was used to absorb the scattered electromagnetic waves towards the surface [52]. With these conditions, the total number of domain elements in the mesh was 68,278 with 4,530 boundary elements.…”