Porous-core Fiber Research Articles

Porous core fiber with hybrid cladding for ultra-flattened dispersion and low loss propagation of terahertz waves

This work proposes a design of a porous-core photonic crystal fiber (PC-PCF) made of a cyclic olefin copolymer, Zeonex, with a hybrid cladding for low-loss terahertz (THz) wave transmission. A combination of circular and elliptical air holes is employed, resulting in a very low material absorption loss of 0.045 cm-1 at Dcore = 450 µm and f = 1 THz. A flat dispersion of 0.73 ± 0.13 ps/THz/cm is obtained for a broad frequency range of 0.5–1.4 THz. Core diameter and frequency response of other key features such as normalized frequency (V-parameter), confinement loss, effective area, nonlinearity and the percentage of the power flow through different sections of the proposed PC-PCF are also analyzed. Comparing to state-of-the-art, our design is superior in terms of loss, dispersion and power fraction. Our proposed design can be manufactured using the established extrusion process and be used for long distance low-loss Terahertz (THz) communication.

Ultra high birefringent dispersion flattened fiber in terahertz regime

Abstract In the current study, a novel Zeonex based porous core photonic crystal fiber (PC-PCF) is presented for polarization-maintaining and dispersion flattened in the terahertz (THz) region. For minimizing the Effective Material Loss (EML), an array of three rectangular and six triangular air holes are surrounded by hexagonal-shaped cladding. Finite Element Method (FEM) is employed through Comsol V5.3a software to design and examine the essential features of the proposed porous core fiber which revealed that it has an extremely small EML of 0.04 cm−1 at 1.2 THz and has almost zero flattened dispersion of 0.8 ± 0.08 ps/THz/cm in 1.0–1.4 THz frequency spectrum. Moreover, the optimum designing parameters offer an extremely high value of birefringence (0.043 at 1.2 THz). Besides, other major features notably bending loss, effective area, and confinement loss are also found to be precise and relatively low. For effective, adaptable and fitting transmission characteristics, this type of design would lay the foundations for broadband THz radiation wide variety of usage in the THz regime.

Negative curvature hollow-core anti-resonant fiber for terahertz sensing.

Hollow-core fibers are advantageous for chemical sensing as they facilitate liquid infiltration into the core over conventional porous core fiber. In addition, the requirement of less bulk material significantly decreases the effective material loss (EML). In this paper, a six circular cladding tube negative curvature hollow-core fiber (NC-HCF) is proposed for chemical sensing. Five different chemicals including chloroform, polylactic acid, CCL3, glycerin, and benzene are proposed to fill the core of the NC-HCF, and sensitivities are evaluated by full vector finite element method-based COMSOL software. Numerical results reveal that the proposed sensor exhibits very high relative sensitivity in a wide range of frequency. The fabrication of the proposed fiber is feasible by existing fabrication facilities as it contains realistic fabrication parameters. Hence, the proposed sensor can potentially be used as a chemical sensor especially in the medical, food, and industrial sectors as the five chemicals mentioned above carry great medical and food significance.

Ultra low loss and dispersion flattened microstructure fiber for terahertz applications

In this paper, a rectangular core hexagonal lattice porous core photonic crystal fiber (PC-PCF) is reported for effectively guiding the terahertz light signal. Finite element method with circular perfectly matched layer boundary condition is employed to find out the propagation characteristics of this proposed porous core fiber. Extensive simulation results of that microstructure fiber over wide frequency range shows that very low effective material loss of 0.035 cm-1, large effective area of 1.79×10-7 m2 and high core power fraction of 36% can be obtained simultaneously. In addition, for same designing condition nearly zero flattened dispersion of 0.46 ± 0.07 ps/THz/cm can be achieved over 600 GHz frequency band in terahertz range. Furthermore, other important parameters like single mode operation, confinement loss and bending loss are also investigated rigorously for the proposed fiber. The excellent results of this optical waveguide will pave the way to implement it in various real life terahertz applications.

Effects of Triangular Core Rotation of a Hybrid Porous Core Terahertz Waveguide

Abstract In this paper, we investigate the effects for rotating the triangular core air hole arrangements of a hybrid design porous core fiber. The triangular core has been rotated in anti-clockwise direction to evaluate the impact on different waveguide properties. Effective Material Loss (EML), confinement loss, bending loss, dispersion characteristics and fraction of power flow are calculated to determine the impacts for rotating the triangular core. The porous fiber represented here has a hybrid design in the core area which includes circular rings with central triangular air hole arrangement. The cladding of the investigated fiber has a hexagonal array of air hole distribution. For optimum parameters the reported hybrid porous core fiber shows a flat EML of ±0.000416 cm−1 from 1.5 to 5 terahertz (THz) range and a near zero dispersion of 0.4±0.042 ps/THz/cm from 1.25 to 5.0 THz. Negligible confinement and bending losses are reported for this new type of hybrid porous core design. With improved concept of air hole distribution and exceptional waveguide properties, the reported porous core fiber can be considered as a vital forwarding step in this field of research.

Hybrid porous core low loss dispersion flattened fiber for THz propagation

This manuscript represents a novel porous core fiber design for Terahertz (THz) propagation with low loss and near zero flat dispersion properties. In this proposed fiber a hexagonal arrangement is used as cladding structure and a hybrid core containing circular and triangular designs is used as the central porous region. The Effective Material Loss (EML), confinement loss and bending loss are investigated for the proposed fiber along with dispersion characteristics. Simulation results show a very low EML of 0.01944cm−1 at 1THz operating frequency with negligible confinement and bending loss. The proposed novel porous design shows 0.55THz range near zero flat dispersion of ±0.05ps/THz/cm at 0.95ps/THz/cm. The reported design consists of only circular shaped air holes with proper core diameter and porosity to simplify the fabrication process. The newly proposed hybrid design in the porous core region can be considered as an improved edition in the research of THz porous core fibers.