Dispersing upconversion nanocrystals in a single silicon microtube

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Upconversion nanocrystals (UCNCs) offer unique optical properties for light manipulation.
• Silica-based microtubes (MTs) are versatile structures for guiding light.
• Integrating UCNCs into MTs can create novel active optical components.

Purpose of the Study:

• To fabricate UCNCs-doped MTs for active light guiding.
• To investigate the optical guiding performance of these UCNCs-MTs.
• To demonstrate optical temperature sensing using UCNCs-MTs.

Main Methods:

• Dispersing Ln3+ (Ln = Yb, Tm, Ho) doped β-NaLuF4 UCNCs into silica MTs via flame heating.
• Characterizing MTs with diameters from 2-30 μm and lengths up to hundreds of microns.
• Measuring fluorescence propagation and evanescent coupling along single UCNCs-MTs.

Main Results:

• UCNCs were successfully dispersed within silica MTs.
• Fluorescence from UCNCs propagated along single MTs and coupled to adjacent MTs via evanescent fields.
• UCNCs-MTs exhibited active waveguide behavior.
• Optical temperature sensing was demonstrated with sufficient sensitivity for thermometry (298-383 K).

Conclusions:

• UCNCs-doped MTs function as active optical waveguides.
• The UCNCs-MTs show promise for integrated optical devices and thermometry applications.