Nanoscale roughness micromilled silica evanescent refractometer.

Area of Science:

• Materials Science
• Optical Engineering
• Nanotechnology

Background:

• Precision machining of silica is crucial for fabricating advanced photonic devices.
• Existing methods face limitations in achieving nanoscale surface roughness and significant depth of cut.

Purpose of the Study:

• To demonstrate a novel milling system for creating precision slots in silica with nanoscale roughness.
• To achieve significant improvements in surface roughness and depth of cut compared to previous methods.
• To integrate these milled slots into functional optical devices.

Main Methods:

• Development and utilization of an in-house precision milling system.
• Machining of slots in silica substrates.
• Characterization of surface roughness (Sa) and depth of cut.
• Integration of milled slots with UV-written waveguides and Bragg gratings.

Main Results:

• Achieved machined slots in silica with a surface roughness of 3.0 nm (Sa).
• Demonstrated a depth of cut of 17 µm.
• Obtained an eight-fold improvement in surface roughness and a forty-fold increase in depth of cut over prior art.
• Successfully created optical refractometers by integrating milled slots with waveguides and gratings.

Conclusions:

• The developed milling system enables high-precision fabrication of silica components for photonics.
• The improved slot characteristics are suitable for advanced optical applications.
• The integration demonstrates the potential for creating novel optical sensing devices like refractometers.