Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

Area of Science:

• Optics and Photonics
• Materials Science
• Microscopy

Background:

• Scanning Near-field Optical Microscopy (SNOM) typically utilizes glass fiber probes.
• Developing robust and high-resolution SNOM probes is crucial for nanoscale imaging.
• Existing probe fabrication methods can involve hazardous materials or have limited lifespans.

Purpose of the Study:

• To introduce and evaluate polymethylmethacrylate (PMMA) optical fiber probes for SNOM applications.
• To demonstrate the feasibility of using PMMA fibers for high-resolution topographical imaging.
• To compare the performance and characteristics of PMMA probes with traditional glass probes.

Main Methods:

• PMMA optical fibers were chemically etched using ethyl acetate to create sharp tips.
• Sharpened fibers were attached to a tuning fork under double resonance conditions.
• Probes were characterized by their quality factors and tested in a Photon Scanning Tunneling Microscope.

Main Results:

• Achieved probe quality factors in the range of 2000-6000.
• Demonstrated excellent topographical resolution, enabling imaging of single DNA molecules.
• Successfully imaged 100nm fluorescent beads using Photon Scanning Tunneling Microscopy.
• PMMA probes showed a significantly longer typical lifetime compared to glass probes.

Conclusions:

• Polymethylmethacrylate (PMMA) optical fiber probes are effective for SNOM.
• These probes offer an easier, safer, and more durable alternative to glass fiber probes.
• The developed PMMA probes enable state-of-the-art nanoscale imaging with high resolution.