Lithium niobate has negative uniaxial birefringence which depends slightly on the stoichiometry of the crystal and on temperature.

[14] The complete protocol implies a LiH induced reduction of NbCl5 followed by in situ spontaneous oxidation into low-valence niobium nano-oxides.

Finally, the stable Nb2O5 is converted into lithium niobate LiNbO3 nanoparticles during the controlled hydrolysis of the LiH excess.

[15] Spherical nanoparticles of lithium niobate with a diameter of approximately 10 nm can be prepared by impregnating a mesoporous silica matrix with a mixture of an aqueous solution of LiNO3 and NH4NbO(C2O4)2 followed by 10 min heating in an infrared furnace.

[20][21] This effect allows for fine manipulation of micrometer-scale particles with high flexibility since the tweezing action is constrained to the illuminated area.

These intense fields are also finding applications in biophysics and biotechnology, as they can influence living organisms in a variety of ways.

Controlled heating of the crystal can be used to fine-tune phase matching in the medium due to a slight variation of the dispersion with temperature.

Periodically poled MgO-doped lithium niobate (PPMgOLN) therefore expands the application to medium power level.

The Sellmeier equations for the extraordinary index are used to find the poling period and approximate temperature for quasi-phase-matching.