Performance of ultra-thin SOI-based resonators for sensing applications

Area of Science:

• Photonics and optical sensing
• Integrated optics
• Nanophotonics

Background:

• Optical ring resonators are key components in sensing applications.
• Evanescent field (EF) penetration depth dictates sensor sensitivity.
• Silicon-on-Insulator (SOI) technology is a standard for integrated photonic devices.

Purpose of the Study:

• To investigate ultra-thin optical ring resonators for enhanced sensing.
• To evaluate the impact of waveguide thickness on evanescent field penetration and sensitivity.
• To assess the temperature stability of ultra-thin resonators.

Main Methods:

• Simulations and experimental characterization of ultra-thin optical ring resonators.
• Fabrication within multi-project wafer (MPW) service constraints (90 nm, 150 nm, 220 nm waveguide thicknesses).
• Comparison with standard transverse electric SOI-based resonator sensors under controlled temperature fluctuations.

Main Results:

• Ultra-thin waveguides (<100 nm) exhibit increased EF penetration depths, leading to higher sensitivities.
• Enhanced sensitivity observed for both bulk and surface sensing applications.
• Ultra-thin resonators demonstrated superior temperature stability compared to conventional SOI resonators.

Conclusions:

• Ultra-thin optical ring resonators represent a promising advancement for high-sensitivity biosensing and lab-on-chip (LoC) systems.
• The proposed designs are compatible with existing MPW fabrication services.
• These sensors offer improved performance and stability for optical sensing applications.