Air Core ARROW Waveguides Fabricated in a Membrane-Covered Trench

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Hollow-core optical waveguides offer potential for low-loss light transmission.
• Fabricating such waveguides with high performance on silicon substrates presents challenges.

Purpose of the Study:

• To design, fabricate, and characterize novel hollow-core anti-resonant reflecting optical waveguides (ARROWs) on silicon.
• To investigate the impact of reflecting layer count on optical loss.

Main Methods:

• Utilized standard microfabrication techniques, including plasma etching, on silicon wafers.
• Fabricated ARROWs with varying numbers of thin-film reflecting layers within membrane-covered trenches.
• Characterized optical loss coefficients of the fabricated waveguides.

Main Results:

• Successfully fabricated four distinct hollow-core ARROW designs.
• Demonstrated a clear trend of decreasing optical loss with an increasing number of reflecting layers.
• Achieved measured optical loss coefficients as low as 1 cm^-1.

Conclusions:

• Hollow-core ARROWs can be fabricated on silicon using established microfabrication processes.
• The number of thin-film reflecting layers is a critical parameter for minimizing optical loss.
• The demonstrated low loss coefficients show promise for integrated optical applications.