Abstract
In this paper,a polarization-maintaining single-mode rectangular-shaped hollow-core waveguide with four segmented air cladding in the terahertz (THz) regime is presented for detecting various toxic industrial chemicals. A new type of injection moldable cyclic olefin copolymer, commercially named as TOPAS is used as the base fiber material for its high optical transmission and high resistance to other chemicals. The finite element method with a perfectly matched layer as the boundary condition is employed for numerical explorations. The proposed sensor exhibits ultra-high relative sensitivity of 99.73% and ultra-low effective material loss of 0.007 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> at 1.6 THz frequency for Toluene in y polarization. This sensor also evinces a high birefringence of 4.16×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> at 1.6 THz frequency. A maximum V parameter of 2.224 has been found at 2.2 THz which ensures the single-mode propagation of light. The sensor shows a very low confinement loss of 3.2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-11</sup> dB/m and a high numerical aperture of 0.3574 at 1.6 THz frequency for Hydrogen Sulfide. This paper also concentrates on other important design parameters such as bending loss, mode field radius, beam divergence and effective area for serviceability of the sensor in the THz region. This sensor can be a very good candidate for various chemical detection as well as other applications in the terahertz regime.
Highlights
Electromagnetic (EM) wave propagation through a dielectric medium occurs via index guided or photonic bandgap mechanism
An optical tunable source (OTS) is required to pass the light through the waveguide to have the interaction with the chemicals
C-type fiber serves as a gas/chemical inlet and helps analyte to flow into the core channel of the photonic crystal fibers (PCF)
Summary
Electromagnetic (EM) wave propagation through a dielectric medium occurs via index guided or photonic bandgap mechanism. A porous core circularly slotted PCF design has achieved high birefringence and low effective material or absorption loss (EML) of 0.07 cm-1. It shows a low bending loss of the order 10-9 dB/m in the operating THz regime [12]. The higher refractive index that gets formed in the core when the targeted toxic chemicals are introduced effectively guides the EM wave through the THz waveguide. Material absorption loss and a good numerical aperture with single-mode behavior at the operating THz frequency make the sensor a prime candidate to be fabricated for sensing purposes. This study focuses on the birefringence effect for the sensing analytes, as the framework for the design makes the analyte to form up an asymmetric core
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
