Ultra-sensitive Chalcogenide-based Photonic Crystal Fiber Sensor Enhanced by Optofluidic Reconfiguration and Engineered Dispersion for Broadband Supercontinuum Generation and Multi-functional Environmental Detection
Year: 2026
Type: preprint
Abstract: We report a multifunctional chalcogenide-based photonic crystal fiber (PCF) that simultaneously achieves broadband supercontinuum (SC) generation and ultra-sensitive multi-parameter environmental detection by synergistically integrating optofluidic reconfiguration, plasmonic field enhancement, and precision dispersion engineering. The proposed structure employs a square-lattice arrangement of circular air holes in an As 2 Se 3 chalcogenide glass substrate, incorporating a centrally positioned gold nanoparticle (Au-NP, diameter d s = 0.18 µm) and a fluid-infiltrated stellar-lattice ring (lattice constant Λ s = 0.2 µm) that enables dynamic real-time tuning of the local refractive index. By optimizing the second-ring air-hole diameter (d 2 = 0.4 µm), the GVD profile achieves a zero-dispersion wavelength (ZDW) of approximately 1.80 µm—tunable by ± 0.12 µm—while maintaining anomalous dispersion throughout the near- to mid-infrared (NIR–MIR) region. Finite-element simulations of the generalized nonlinear Schrödinger equation (GNLSE) confirm that, under a 200 fs, sech 2 -shaped pump pulse at 1.80 µm with ~ 8 kW peak power, the SC spectrum spans 1.2–3.0 µm at the − 30 dB level. The nonlinear parameter reaches γ ≈ 450 W −1 km − 1 at the pump wavelength, driven by the high Kerr nonlinearity of As 2 Se 3 (n 2 ≈ 10 −14 cm 2 /W) and the tight mode confinement (A eff < 2 µm 2 ). For refractive-index sensing, the Au-NP-mediated localized surface plasmon resonance (LSPR) and the optofluidic ring collectively yield a sensitivity of S ≈ 3000 nm/RIU with a refractive-index resolution of ∼3.3 × 10 − 5 RIU—surpassing numerous state-of-the-art designs—while the confinement loss remains below 10 − 4 dB/cm across the 1.5–2.5 µm window. The structure concurrently responds to temperature, hydrostatic pressure, and chemical composition variations, confirming its genuine multi-parameter sensing capability. These results establish the proposed PCF as a powerful, reconfigurable, and highly sensitive platform for next-generation photonic systems spanning environmental monitoring, chemical spectroscopy, and biomedical diagnostics.
Source: Research Square
Institution: Islamic Azad University Kazeron
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204440339