Microbubble-probe WGM resonators enable displacement measurements with high spatial resolution

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Whispering gallery mode resonators are sensitive to external perturbations.
• Microbubble-based structures offer unique optical properties.
• High-resolution displacement sensing is crucial for various scientific and industrial applications.

Purpose of the Study:

• To propose and characterize a novel microbubble-probe whispering gallery mode resonator.
• To evaluate its performance for high-resolution displacement sensing.
• To demonstrate its potential for precision measurement.

Main Methods:

• Fabrication of the microbubble-probe resonator using CO2 laser machining.
• Characterization of the resonator's quality factor.
• Experimental evaluation of displacement sensing capabilities, including resolution and measurement span.

Main Results:

• Achieved a universal quality factor exceeding 10^6.
• Demonstrated a displacement resolution of 74.83 pm.
• Estimated a measurement span of 29.44 µm with micron-level spatial resolution.

Conclusions:

• The developed microbubble-probe resonator is the first of its kind for displacement measurement.
• The sensor exhibits superior performance in displacement resolution and spatial resolution.
• This technology holds significant potential for high-precision sensing applications.