A Tunable Optical Bragg Grating Filter Based on the Droplet Sagging Effect on a Superhydrophobic Nanopillar Array

Area of Science:

• Optofluidics
• Nanotechnology
• Photonics

Background:

• Nanostructures are crucial for superhydrophobic surfaces and enhancing optical devices.
• Integrating microfluidics and optics within nanostructures remains a significant challenge.

Purpose of the Study:

• To propose and simulate a novel microfluidic-controlled tunable filter.
• To demonstrate the integration of microfluidics and optics in nanostructures for tunable filtering and sensing.

Main Methods:

• Numerical simulation of a microfluidic-controlled tunable filter.
• Design features periodic micro/nanopillars on a planar waveguide.
• Tunability achieved by controlling liquid droplet sagging depth into pillars.

Main Results:

• Achieved a narrow bandwidth of 0.4 nm.
• Demonstrated a wide wavelength tuning range of over 25 nm.
• Proposed scheme adaptable for refractive index sensing with 103 nm/RIU sensitivity.

Conclusions:

• The proposed microfluidic-based tunable optofluidic waveguide Bragg grating filter shows promising performance.
• The integrated nanostructure design offers a versatile platform for tunable optical filtering and sensing applications.