Related Experiment Video
Updated: Jun 29, 2026
09:35
Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents
Published on: May 1, 2012
13.0K
Design of a High Q-Factor Label-Free Optical Biosensor Based on a Photonic Crystal Coupled Cavity Waveguide
Reyhaneh Jannesari1, Gerald Pühringer1, Gerald Stocker2
1Institute for Microelectronics and Microsensors, Johannes Kepler University, 4040 Linz, Austria.
Sensors (Basel, Switzerland)
|January 11, 2024
Summary
This study introduces a silicon-based photonic crystal biosensor for label-free detection. The coupled cavity waveguide design achieves high sensitivity (203 nm/RIU) and quality factor (13,360) for refractive index changes.
Area of Science:
- Photonics
- Nanotechnology
- Biomedical Engineering
Background:
- Silicon-based on-chip sensing is a rapidly growing research area.
- Label-free biosensors offer sensitive detection without requiring analyte labeling.
Purpose of the Study:
- To design and analyze a coupled cavity waveguide (CCW) based on a slab photonic crystal structure for label-free biosensing.
- To investigate the sensor's sensitivity to refractive index changes.
Main Methods:
- Utilized the plane wave expansion (PWE) method to analyze coupled cavity waveguide modes.
- Employed the finite difference time domain (FDTD) technique to simulate transmission spectrum, quality factor, and sensitivity.
- Designed a photonic crystal with holes in a triangular lattice, incorporating defects for enhanced sensitivity.
Main Results:
- Achieved a high sensitivity of 203 nm/RIU.
- Obtained a quality factor of 13,360.
- Demonstrated effective light coupling into the coupled cavity waveguide.
Conclusions:
- The designed photonic crystal biosensor shows significant potential for label-free detection of analytes.
- The sensor's high sensitivity and quality factor make it suitable for detecting minute refractive index variations.
- This silicon-based platform offers a promising approach for advanced on-chip sensing applications.
