Growth and basic investigations of LiNbO3 single crystals doped with Dy 3+ ions

摘要

Lithium niobate crystals doped with Dy3+ ions were grown by the Czochralski method. The doping concentrations were 0.3, 1. and 1.7 at. %. Respectively The dopant distribution was measured by the electron microprobe "JOEL - JXA 50 A" - type device, and from these measurements the segregation coefficient has been found to be close to unit (k =0.8 Optical homogeneity of crystals was investigated by the conoscopic and polarimetric methods. For the Z - optical axis direction it was found that the maximum residual birefringence (not exceeding 1.5 x 10-1), involved by residual stresses. occured at the perimeters of the crystals, and the remaining crystalline areas were almost entirely free from excessive stresses. The absorption characteristics in the wavelength range of 200 - 6000 nm were measured. The photoluminescence characteristics were also measured in the visible part of the spectrum. It has been found that an important feature associated with luminescence of the Dy3+ in LiNbO3 is its high intensity and long decay time. From this it can be concluded that LiNbO3: Dy3- is particularly well suited for visible lasers.