Super-Resolution Imaging With Fluorotellurite Glass Microspheres

Area of Science:

• Optical Nanoscopy
• Materials Science
• Microscopy

Background:

• Conventional optical microscopy is limited by diffraction.
• Microsphere-lens-assisted optical nanoscopy overcomes diffraction limits.
• High-refractive-index materials are crucial for advanced nanoscopy.

Purpose of the Study:

• To investigate fluorotellurite (TBY) glass microspheres for optical nanoscopy.
• To characterize their optical properties and focusing capabilities.
• To demonstrate their application in super-resolution imaging.

Main Methods:

• Fabrication of TBY glass microspheres using a floating-zone melting technique.
• Characterization of microsphere properties (sphericity, surface, size, refractive index, transmittance).
• Ray-tracing and electromagnetic simulations for near-field focusing analysis.
• Super-resolution imaging of nanoscale samples (anodic aluminum oxide, gratings).
• Development of an ultramicroscopic objective (UO) module.

Main Results:

• TBY microspheres exhibit excellent sphericity, ultra-smooth surfaces, and diameters from 10-200 μm.
• Refractive index of ~1.9 and up to 85% visible transmittance.
• Demonstrated super-resolution imaging with 50 nm resolution and ~4.34× magnification.
• Identified critical influence of image-plane selection and axial alignment on image quality.
• Developed a reusable UO module compatible with commercial microscopes.

Conclusions:

• TBY glass microspheres are effective for super-resolution optical nanoscopy.
• Optimized microsphere parameters and alignment are key for high-quality imaging.
• The developed UO module offers practical advantages for nanoscale imaging.
• Fluorotellurite glass shows potential for deep-tissue, multi-band, and laser micro-machining applications.