Enhancement of Exposed Evanescent Field in a Photonic Crystal Fiber with Triangular Air Holes around the Core for Chemical Sensing

Author(s):  
W. L. Ng ◽  
D. C. Tee ◽  
K. S. Yeo ◽  
G. A. Mahdiraji ◽  
G. R. Lin ◽  
...  
Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1799
Author(s):  
Tianyu Yang ◽  
Liang Zhang ◽  
Yunjie Shi ◽  
Shidi Liu ◽  
Yuming Dong

A photonic crystal fiber (PCF) with high relative sensitivity was designed and investigated for the detection of chemical analytes in the terahertz (THz) regime. To ease the complexity, an extremely simple cladding employing four struts is adopted, which forms a rectangular shaped core area for filling with analytes. Results of enormous simulations indicate that a minimum 87.8% relative chemical sensitivity with low confinement and effective material absorption losses can be obtained for any kind of analyte, e.g., HCN (1.26), water (1.33), ethanol (1.35), KCN (1.41), or cocaine (1.50), whose refractive index falls in the range of 1.2 to 1.5. Besides, the PCF can also achieve high birefringence (∼0.01), low and flat dispersion, a large effective modal area, and a large numerical aperture within the investigated frequency range from 0.5 to 1.5 THz. We believe that the proposed PCF can be applied to chemical sensing of liquid and THz systems requiring wide-band polarization-maintaining transmission and low attenuation.


2021 ◽  
pp. 2150306
Author(s):  
Pibin Bing ◽  
Guifang Wu ◽  
Zhongyang Li ◽  
Sheng Yuan ◽  
Hongtao Zhang ◽  
...  

The photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) technology has flexibility in birefringence, negative dispersion, effective area and nonlinearity and has become a widely studied new fiber. However, there are many problems in the practical application of the sensor, such as complex structure design, not easy to prepare, the low sensitivity of sensing detection, narrow range of refractive index detection of analytes, which greatly limits the application range and functions of PCF sensors. To solve the above problems, this paper adopts a structure with a longer vertical distance between the D-shaped large air hole channel and the core. The energy of the core conduction mode is better limited by the cladding to transmit in the core, and the plasma mode is enhanced, which can effectively increase the wavelength sensitivity. In this paper, the hexagonal double-clad air hole structure and the D-type structure are combined to ensure a simple structure and facilitate manufacturing and production, while the wavelength sensitivity is also greatly improved. The wavelength sensitivity of the dual sample channel can reach up to 16200 nm/RIU and 15800 nm/RIU, which has broad application prospects in the field of high-sensitivity detection.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaymaa Riyadh Tahhan ◽  
Hadeel K. Aljobouri

AbstractStimulant abuse enhances dopamine release, thereby causing increased excitation. Any extent of stimulant abuse can considerably harm the user. Thus, methods of detecting stimulants must be precise, accurate, and reliable. A novel terahertz (THz) photonic crystal fiber with a Topas substrate is designed and rigorously investigated for detecting liquid amphetamine, cocaine, and ketamine. The fiber structure has a pentagonal shape and comprises circular air holes in the core and cladding spatial extents. As shown in finite element simulation, the proposed fiber yields a high relative sensitivity of approximately 80 % when any of the liquid stimulants is infiltrated in the core air holes. At 1 THz operating frequency, the proposed fiber produces a large effective mode area, negligible confinement loss, and extremely low bending and effective material losses. Other THz waveguiding properties, such as core power fraction and total loss, are also studied. Lastly, a positive and negative 2 % fabrication tolerance is set to ensure seamless potential practical realization of the fiber.


2020 ◽  
Vol 12 (4) ◽  
pp. 94
Author(s):  
Mohammad Saiful Islam ◽  
Anwar Sadath ◽  
Md. Rakibul Islam ◽  
Mohammad Faisal

Nowadays photonic crystal fiber (PCF) is used for sensing purposes in different fields. In this work, we have proposed a PCF based chemical (Benzene and Ethanol) sensor. Finite Element Method (FEM) based software COMSOL 5.3a is used to investigate the numerical characteristics for the proposed structure. From the numerical analysis, we obtained high sensitivity with low losses for an optimum core diameter of 210 µm. Our proposed PCF works on a broad range of core diameters and THz frequency spectra. The fabrication of this model is very simple due to its simplistic design structure. Full Text: PDF ReferencesMd.F.H. Arif, Md.J.H. Biddut, "A new structure of photonic crystal fiber with high sensitivity, high nonlinearity, high birefringence and low confinement loss for liquid analyte sensing applications", Sensing Bio-Sensing Res. 12, 8 (2017). CrossRef P. Kumar, Md.H. Bikash, K. Ahmed, S. Sen, "A Novel Hexahedron Photonic Crystal Fiber in Terahertz Propagation: Design and Analysis", Photonics 6(1), 32 (2019). CrossRef S. Asaduzzaman, K. Ahmed, T. Bhuiyan, T. Farah, "Hybrid photonic crystal fiber in chemical sensing", SpringerPlus 5, 748 (2016). CrossRef Md.S. Islam, J. Sultana, J. Atai, D. Abbott, S. Rana, M.R. Islam, "Ultra low-loss hybrid core porous fiber for broadband applications", App. Opt. 56(4), 1232 (2017). CrossRef S. Atakaramians, S. Afshar, H. Ebendorff-Heidepriem, M. Nagel, B.M. Fischer, D. Abbott, T.M. Monro, "THz porous fibers: design, fabrication and experimental characterization", Opt. Expr. 17(16), 14053 (2009). CrossRef


2018 ◽  
Vol 26 (17) ◽  
pp. 21939 ◽  
Author(s):  
Tomasz Stefaniuk ◽  
Grzegorz Stępniewski ◽  
Dariusz Pysz ◽  
Ryszard Stępień ◽  
Ryszard Buczyński

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