Ultra-high order mode-assisted optical differentiator for edge detection with high tunability

Area of Science:

• Optics and Photonics
• Waveguide Optics
• Metamaterials

Background:

• The photonic spin Hall effect (PSHE) describes the spin-dependent spatial separation of photons.
• Optical differentiators are crucial for image processing and feature extraction.
• Metal-cladding waveguides offer unique optical properties for manipulating light.

Purpose of the Study:

• To develop a highly tunable optical spatial differentiator.
• To leverage the photonic spin Hall effect for enhanced optical differentiation.
• To demonstrate the application of this differentiator in tunable resolution edge detection.

Main Methods:

• Utilizing ultra-high order modes in a symmetrical metal cladding waveguide.
• Exploiting the narrow peak width and low trough of the Fresnel reflection coefficient spectrum at resonant angles.
• Implementing polarization transformation and extinction for differential operation.

Main Results:

• Achieved high sensitivity to incident angle changes (∂(|rs/rp|)/∂θ up to 10^7).
• Demonstrated tunable resolution edge images by adjusting the incident angle.
• Verified the differential operation of the output field.

Conclusions:

• The proposed optical spatial differentiator based on PSHE offers high tunability and sensitivity.
• This technology has potential applications in cellular and molecular imaging.
• The scheme allows for adjustable resolution edge detection through incident angle control.