Highly birefringent vaterite microspheres: production, characterization and applications for optical micromanipulation

Opt Express. 2009 Nov 23;17(24):21944-55. doi: 10.1364/OE.17.021944.


This paper reports on a simple synthesis and characterization of highly birefringent vaterite microspheres, which are composed of 20-30 nm sized nanocrystalls. Scanning electron microscopy shows a quite disordered assembly of nanocrystals within the microspheres. However, using optical tweezers, the effective birefringence of the microspheres was measured to be Deltan = 0.06, which compares to Deltan = 0.1 of vaterite single crystals. This suggests a very high orientation of the nanocrystals within the microspheres. A hyperbolic model of the direction of the optical axis throughout the vaterite spherulite best fits the experimental data. Results from polarized light microscopy further confirm the hyperbolic model.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anisotropy
  • Birefringence*
  • Equipment Design
  • Lasers
  • Microscopy, Electron, Scanning / methods*
  • Microscopy, Electron, Transmission / methods
  • Microspheres*
  • Nanoparticles
  • Nanotechnology / methods
  • Optics and Photonics*
  • Particle Size
  • X-Ray Diffraction