Browsing by Author "Hossain, Md Selim"

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Design and Numerical Analysis of a Novel Photonic Crystal Fiber Based Chemicals Sensor in the THz Regime
(Elsevier, 2022-07-22) Hossain, Md Selim; Hossen, Rakib; Alvi, Syada Tasmia; Sen, Shuvo; Al-Amin, Md.; Hossain, Md. Mahabub
We presented a decagonal cladding and hexahedron core-based photonic crystal fiber (PCF) to sense chemicals in the terahertz frequency (THz). Circular air holes (CAHs) in the cladding region make up the proposed sensor. A wide variety of frequencies were evaluated to analyze the sensor’s performance in terms of sensitivity, confinement loss, and effective material loss respectively. We designed and quantitatively analyzed the optical properties of our proposed hexahedron-based PCF sensor using the finite element method (FEM). Square-shaped air hole length, strut, and core size have also been researched to improve the performance of the proposed sensor’s sensing components and fabrication tolerance. At ideal conditions, the suggested PCF sensor has a maximum relative sensitivity of 94.65%, confinement loss of 6.01 × 10− 8 cm− 1 , effective material loss (EML) of 9.16 × 10− 4 cm− 1 , and effective mode area (EMA) of 1.35 × 10− 7 m2 . We are confident that the suggested sensor’s optimized geometrical structure will be manufacturing-friendly, as well as the sensor’s contribution to practical uses. Furthermore, our proposed PCF fiber will be ideal in the terahertz (THz) regions for various optical communication applications and medicinal signals.
Evaluation of THz wave transmission performance in TOPAS-based heptagonal photonic crystal fiber (He-PCF)
(2024-02-15) Hossain, Md Selim; Hossen, Rakib; Al-Amin, Md; Ahmed, Sabbir; Sen, Shuvo
PCF denotes photonic crystal fiber which is utilized for terahertz (THz) waveguides and cladding in the shape of a hexagon with two elliptical air apertures (AHs), which are discussed. Such differentiation is made: When the frequency is 1 THz, effective material loss (EML) to a minimum of 0.028 cm−1 has been achieved. Making use of the heptagonal photonic crystal fiber (He-PCF) architecture, every simulation result utilizing COMSOL Multiphysics software implements the perfectly match layer (PML) and finite element method (FEM) boundary conditions. The He-PCF fiber demonstrates an effective mode loss (EML) of 0.028 cm−1 that is negligible, a substantial effective area (EA) measuring 7.31 × 10−8 m2 and an 80 % power concentration encompassing the central area at 1 THz frequency. Furthermore, regarding crucial optical guiding aspects like confinement loss, dispersion, and modality, a small study with respect to power fraction along with effective mode area (EMA) has again been conducted. Here, He-PCF THz waveguide is anticipated to provide a notable improvement in the current design for the communication field. Moreover, our suggested the PCF demonstrates perception by a solitary mode, as indicated through the utilization of the V-parameter, across a range in frequency spanning among 0.80 and 3 THz. Thus, it is anticipated that the layout of He-PCF fibers will facilitate efficient transmission of terahertz (THz) signals in a variety of communication applications.
Fiber design and performance analyses for optical multiplexing: terahertz optical communications
(2024-04-25) Kabir, Md Anowar; Kumar Paul, Bikash; Hossain, Md Selim; Shahin Uddin, Muhammad; Morshed, Monir
Multiplexing is the process of combining multiple signals at a single channel. Orbital Angular Momentum (OAM) is one of the main multiplexing techniques for optical data transmissions. This paper examines and suggests a hollow core with four layers of semilunar air-hole-shaped circular photonic crystal fiber (PCF) capable of transmitting terahertz (THz) OAM information-carrying modes. By using the full vector finite element method (FEM), OAM multiplexing is analyzed for the proposed fiber. All the THz OAM-based factors are analyzed at a frequency band ranging from 400 GHz to 800 GHz. For the first time, some important PCF factors such as effective refractive index difference (ERID), dispersion profile (DP), OAM purity, confinement loss (CL), effective mode area (ERA), and numerical aperture (NA) are quantitatively discussed with applications. The proposed design supports 50 OAM modes with ERID up to 10−3. The PCF has a CL of approximately 10–10 dB cm−1 and the lowest dispersion profile is 0.3581 ps/THz/cm. Furthermore, the OAM purity is around 97%. Nonetheless, the proposed design can be used in THz-OAM transmission and high optical fiber communications.
Sensitivity Analysis for Detecting Chemicals by the Optical Chemical Sensor Based Photonic Crystal Fiber (PCF) in the Terahertz (THz) Regime
(Physica Scripta, 2021-12-23) Hossain, Md Selim; Faruq, Md Omar; Rana, Md Masud; Sen, Shuvo; Haque, Md Dulal; Azad, Mir Mohammad
This research article demonstrates a good simulation result for identifying and detecting various industrial chemicals in a Terahertz (THz) waveguide with a new heptagonal, five layers of heptagonal photonic fiber elliptic form, heptagonal cladding shape (H-PCF). COMSOL 4.2 software based on finite element (FEM) methods and perfectly matched layers check our composition (PML). The different chemicals are also differentiated and identified by each other in different parameters H-PCF fibers show a high relative sensitivity of ethanol of approximately 86.50 percent after numerical analysis, Benzene around 89.35%, and water around 85.15% at a frequency of around 0.7 THz. In our experiment, we obtained very low confinement losses at 1 terahertz (THz) such as 5.95 × 10−08 dB/m for Ethanol 6.67 × 10−08 dB/m for Benzene, and 5.80 × 10−08 dB/m for water. Regarding these results, we can strongly recommend that our proposed heptagonal photonic crystal fiber (H-PCF) will be more congenial in biomedical, bio-medicine, and industrial areas for the identification and detection of various types of chemicals with the help of a THz waveguide.