Multi-target detection and sizing of single nanoparticles using an optical star polygon microcavity

Area of Science:

• Optics and Photonics
• Nanotechnology
• Materials Science

Background:

• Existing nanoparticle detection methods often lack miniaturization and multi-target capabilities.
• Optical microcavities offer potential for enhanced light-matter interactions crucial for sensing.
• High-quality factor (Q-factor) cavities are essential for sensitive optical detection.

Purpose of the Study:

• To design and simulate a miniaturized optical detector for single and multiple nanoparticle detection.
• To investigate the use of a star polygon microcavity for enhanced light-matter interactions.
• To demonstrate the capability for simultaneous detection and sizing of nanoparticles.

Main Methods:

• Utilized a 3 µm-radius optical star polygon microcavity supporting high-Q resonant modes.
• Simulated light localization at the corners of the star-shaped polygon for enhanced sensing.
• Investigated the effect of nanoparticle placement on microcavity Q-factor and detection sensitivity.

Main Results:

• Achieved enhanced light-matter interactions by positioning nanoparticles at the microcavity corners.
• Demonstrated high-precision detection of 3 nm radius polystyrene nanoparticles via numerical simulations.
• Showcased the ability to determine nanoparticle size and number using the cavity's triangular corners as rulers.

Conclusions:

• The star polygon microcavity enables miniaturized, simultaneous multi-target nanoparticle detection with high precision.
• The detector design is robust, with minimal impact on Q-factor when detecting multiple particles.
• Potential applications span biomedicine, environmental monitoring, and other fields requiring sensitive nanoparticle analysis.