Engineering order in the lattice of LiNbO3 crystal written in glass by femtosecond laser

Erbium doped single crystals of lithium niobate were grown within the bulk of 0.075 Er2O3 – 37 Li2O – 37 Nb2O5 – 26 SiO2 glass using a femtosecond pulsed laser. Combined excitation emission spectroscopy was used to show incorporation of erbium into the laser written crystal lattice. Laser power and scanning speed were held constant at optimized values, while bulk sample temperature was systematically varied to study the impact on the crystal growth. Using electron backscatter diffraction to study the transverse cross-sections of grown crystals, control over the lattice rotation rates and crystal size were realized. Unlike changing other parameters, a range of temperatures were found to have substantial impacts on crystal growth, without inhibiting the ability to maintain single crystal formation over long distances.