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Biosensors based on novel nonlinear delta-function photonic crystals comprising weak nonlinearities.
Ahmed Mehaney1, Mazen M Abadla2, Hussein A Elsayed3
1TH-PPM Group, Physics Department, Faculty of Science, Beni-Suef University, Beni Suef, 62512, Egypt. ahmed011236@science.bsu.edu.eg.
Scientific Reports
|October 21, 2022
Summary
This study introduces a nonlinear photonic crystal sensor for detecting sodium iodide (NaI) concentrations. The novel GaP-based structure achieves high sensitivity and a low detection limit for NaI solutions.
Area of Science:
- Photonics
- Materials Science
- Chemical Sensing
Background:
- Photonic crystals offer unique light manipulation properties.
- Nonlinearity in photonic structures enables novel sensing mechanisms.
- Detecting varying concentrations of sodium iodide (NaI) is crucial in various applications.
Purpose of the Study:
- To propose and investigate a novel nonlinear delta-function photonic crystal for NaI solution detection.
- To analyze the impact of nonlinearity on defect-like resonance formation within the photonic band gap.
- To evaluate the sensor's sensitivity and detection limit for NaI solutions.
Main Methods:
- A proposed structure comprising 50 delta stacks of Gallium Phosphide (GaP) in NaI solution.
- Utilizing weak defocusing nonlinearity (order of 10-6 (V/m)-2).
- Numerical analysis of transmittance, refractive index effects, and nonlinear coefficient impact.
Main Results:
- A defect-like resonance is formed within the photonic band gap due to nonlinearity.
- Resonant peak splitting observed at a critical nonlinearity of approximately -12 × 10-6 (V/m)-2.
- Achieved high sensitivity of 409.7 nm/RIU and a detection limit of 0.0008.
Conclusions:
- The nonlinear photonic crystal effectively detects NaI concentrations without requiring a defect.
- The sensor demonstrates high performance metrics, including sensitivity and detection limit.
- This approach offers a promising method for sensitive and accurate NaI detection.
