Browsing by Author "Yakasai, Izaddeen"

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Design and Simulation of Photonic Crystal Fiber for Liquid Sensing
(MDPI, 2021-01-12) Maidi, Abdul; Yakasai, Izaddeen; Abas, Emeroylariffion; Nauman, Malik; Apong, Rosyzie; Kaijage, Shubi; Begum, Feroza
A simple hexagonal lattice photonic crystal fiber model with liquid-infiltrated core for different liquids: water, ethanol and benzene, has been proposed. In the proposed structure, three air hole rings are present in the cladding and three equal sized air holes are present in the core. Numerical investigation of the proposed fiber has been performed using full vector finite element method with anisotropic perfectly match layers, to show that the proposed simple structure exhibits high relative sensitivity, high power fraction, relatively high birefringence, low chromatic dispersion, low confinement loss, small effective area, and high nonlinear coefficient. All these properties have been numerically investigated at a wider wavelength regime 0.6–1.8 μm within mostly the IR region. Relative sensitivities of water, ethanol and benzene are obtained at 62.60%, 65.34% and 74.50%, respectively, and the nonlinear coefficients are 69.4 W−1 km−1 for water, 73.8 W−1 km−1 for ethanol and 95.4 W−1 km−1 for benzene, at 1.3 μm operating wavelength. The simple structure can be easily fabricated for practical use, and assessment of its multiple waveguide properties has justified its usage in real liquid detection.
Modelling and simulation of novel liquid-infiltrated PCF biosensor in Terahertzfrequencies
(IET Optoelectronics, 2020-07-23) Suhaimi, Nurul; Yakasai, Izaddeen; Abas, Emeroylariffion; Kaijage, Shubi; Begum, Feroza
The liquid-infiltrated photonic crystal fibre (LI-PCF) is proposed for guiding terahertz radiation. Geometricalasymmetry is achieved by introducing a large ellipse in the core. By filling the ellipse with liquid cocaine, the optical properties ofthe photonic crystal fibre (PCF) are theoretically examined using finite element method-based COMSOL multiphysics software.At an operating frequency of 1 THz, the proposed LI-PCF demonstrates a sensitivity of 87.02% and confinement loss in theorder of 10−4 cm−1. The PCF also demonstrates extremely low effective material loss <0.01 cm−1, a birefringence of 0.018, largeeffective mode area of 1.11 × 105 μm2, a high numerical aperture of 0.45 and near-zero ultra-flattened chromatic dispersion of1.4351 ± 0.5883 ps/THz/cm. The design simplicity and high sensitivity, strong confinement factor, low material losses and highbirefringence of the fibre suggest that the proposed fibre may be convenient for PCF-based cocaine sensing, for application inthe security and defence industries
Proposal for a Quad-Elliptical Photonic Crystal Fiber for Terahertz Wave Guidance and Sensing Chemical Warfare Liquids
(MDPI, 2019-07-08) Yakasai, Izaddeen; Abas, Emeroylariffion; Kaijage, Shubi; Caesarendra, Wahyu; Begum, Feroza
A porous-core photonic crystal fiber based on a cyclic olefin homopolymer (Zeonex) is proposed; it shows high birefringence, high core power fraction, low losses, and near-zero flat dispersion. The fiber’s core was designed with quad-elliptical (QE) air holes with its center occupied by bulk background material. The superiority of the QE design over the commonly adopted tri- and penta-elliptical (TE and PE) core designs is demonstrated. The presence of the bulk material at the core center and the geometrical configuration cause a broad contrast in phase refractive indices, thereby producing high birefringence and low transmission losses. A high birefringence of 0.096 was obtained at 1.2 THz, corresponding to a total loss of 0.027 cm−1 and core power fraction of approximately 51%. The chromatic dispersion and effective area of the reported fiber were also characterized within a frequency range of 0.4–1.6 THz. The QE air holes were then filled with chemical warfare agents, namely, tabun and sarin liquids. Then, the relative sensitivity, confinement loss, fractional power flow, and effective material loss (EML) of the sensor were calculated. Nearly the same relative sensitivity (r = 64%) was obtained when the QE core was filled with either liquid. Although the obtained EML for tabun was 0.033 cm−1 and that for sarin was 0.028 cm−1, the confinement loss of the fiber when it was immersed in either liquid was negligible. The proposed fiber can be fabricated using existing fabrication technologies. Moreover, it can be applied and utilized as a THz radiation conveyor in a terahertz time domain spectroscopy system for remote sensing of chemical liquids in the security and defense industries.