Incident Exposure Energy Research Articles

Effect of Zr4+ concentration on the segregation coefficient and exposure energy of Zr:Fe:Cu:LiNbO3 crystal

A series of Zr:Fe:Cu:LiNbO3 crystals with distinct Zr4+ ion doping concentrations (0, 2, and 4 mol%) were grown using the Czochralski method. Subsequently, the segregation coefficient of doped ions in the crystal was analyzed by an inductively coupled plasma-atomic emission spectrometer. The lattice constant and defect structure of the crystal were measured by X-ray powder diffraction. The light-induced scattering of Zr:Fe:Cu:LiNbO3 crystal was analyzed by the threshold effect of incident exposure energy flux and the same as the change in Zr4+ ion doping concentration. When the Zr4+ ion concentration changes to 4 mol%, the exposure energy was close to 811.37 J/cm2, which is about 192 times that of the 0 mol% Zr4+.

The dependence of light-induced scattering and defect structure on the Li/Nb ratio of In:Ru:Fe:LiNbO3 crystal

In:Ru:Fe:LiNbO3 crystals were grown by the Czochralski method with various Li/Nb ratios of 0.94, 1.05, 1.20 and 1.38 in the melt. The segregation coefficient of In3+, Ru4+ and Fe3+ ions were analyzed by an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The infrared transmittance spectra were measured to investigated the defect structure of In:Ru:Fe:LiNbO3 crystals. The light-induced scattering of In:Ru:Fe:LiNbO3 crystals was characterized quantitatively via the incident exposure energy method. The results show that the ability to resistance light-induced scattering enhanced with the increase of the Li/Nb ratio. The dependence of light-induced scattering on the defect structure of In:Ru:Fe:LiNbO3 crystals was discussed in detail based on the Li-site vacancy model.

Optical properties of Mg2+, Yb3+, and Ho3+ tri-doped LiNbO3 crystals**Project supported by the National Natural Science Foundation of China (Grant No. 51301055), the Youth Science Fund of Heilongjiang Province, China (Grant No. QC2015061), the Special Funds of Harbin Innovation Talents in Science and Technology Research, China (Grant No. 2015RQQXJ045 ), and the Science Funds for the Young Innovative Talents of

A series of LiNbO3 crystals tri-doped with Mg, Yb, and Ho are grown by the conventional Czochraski technique. The concentrations of Mg, Yb, and Ho ions in Mg:Yb:Ho:LiNbO3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry. The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal. The light-induced scattering of Mg:Yb:Ho:LiNbO3 crystal is quantitatively described via the threshold effect of incident exposure energy flux. The exposure energy () is calculated to discuss the optical damage resistance ability. The exposure energy of Mg(7 mol):Yb:Ho:LiNbO3 crystal is 709.17 J/cm2, approximately 425 times higher than that of the Mg(1 mol):Yb:Ho:LiNbO3 crystal in magnitude. The blue, red, and very intense green bands of Mg:Yb:Ho:LiNbO3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties. The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process. The up-conversion emission mechanism is discussed in detail. This study indicates that Mg:Yb:Ho:LiNbO3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices.

Influence of [Li]/[Nb] ratios (0.85, 0.94, 1.05, 1.20 and 1.38) on dopant occupancy and light-induced scattering of Hf:Yb:Ho:LiNbO3

Hf:Yb:Ho:LiNbO3 crystals with various [Li]/[Nb] ratios (0.85, 0.94, 1.05, 1.20 and 1.38) were grown by Czochraski technique. In this report, the defect structure and dopant occupancy of Hf:Yb:Ho:LiNbO3 crystals were determined by IR transmission spectrum. In all cases, the effective distribution coefficients are less than 1. Furthermore, the light-induced scattering of Hf:Yb:Ho:LiNbO3 crystals was quantitatively measured via the incident exposure energy. The exposure energy of Hf:Yb:Ho:LiNbO3 crystal with the [Li]/[Nb] ratios of 1.38 is 763.84 J/cm2, approximately 326 folds than that of the Hf:Yb:Ho:LiNbO3 crystal ([Li]/[Nb] = 0.85) in magnitude.

Effect of In3+ concentration on the photorefraction and scattering properties in In:Fe:CU:LiNbO3 crystals at 532 nm wavelength

The LiNbO3 crystals doped with Fe2O3, CuO and various In2O3, respectively, have been grown by the Czochralski method in air atmosphere. The photorefractive properties at 532nm wavelength were measured by using the typical two-wave coupling experiments. Meanwhile, the incident exposure energy flux threshold for the light-induced scattering was characterized to investigate the scattering properties of the crystals. The results show that the response time shortens, the recording sensitivity improves, and the light-induced scattering decreases with the increasing In3+ ions concentration. However, the doping of In3+ ions leads to the decrease of the diffraction efficiency and the gain coefficient. So, the appropriate In3+ ions concentration should be doping in In:Fe:Cu:LiNbO3 crystals to adapt our practical application in the green light region photorefractive holographic recording.

Dopant occupancy and increased exposure energy of Zr:Yb:Ho:LiNbO3 crystals

Yb:Ho:LiNbO3 crystals tridoped with various Zr4+ concentrations (0, 1, 2 and 5mol%) were grown by Czochraski technique. Defect structure and dopant occupancy of Zr:Yb:Ho:LiNbO3 crystals were determined by IR transmission spectrum. The effective distribution coefficient of Zr ion increases with increasing ZrO2 concentration in the melts, which is near to one. The light-induced scattering of Zr:Yb:Ho:LiNbO3 crystals was quantitatively measured via the incident exposure energy. The exposure energy of Zr (5mol%):Yb:Ho:LiNbO3 crystal is 49.33J/cm2, which is two orders higher than that of Yb:Ho:LiNbO3 crystal in magnitude. The photoconductivity is key factor to understand the internal relationship between the dopant occupancy and exposure energy of the crystals.

Influence of In3+ ions concentration on the defect structure and light-induced scattering of Ce:Mn:LiNbO3 crystals

Congruent Ce (0.1mass%):Mn (0.015mass%):LiNbO3 crystals codoped with In2O3(Xmol%, X=0, 0.5, 1 and 1.5) were grown by the Czochralski method in the air. The In contents in the crystals were measured by an inductively coupled plasma spectrometry (ICP-AES). The ultraviolet–visible and infrared transmittance spectra were characterized to investigate defect structures of these crystals. The light- induced scattering of In:Ce:Mn:LiNbO3 crystals was characterized quantitatively via the incident exposure energy. The results showed that the exposure energy of In (3mol%):Ce:Mn:LiNbO3 is 29.83J/cm2,which is approximately 20 times larger than that of Ce:Mn:LiNbO3. The relationship between the light-induced scattering and the defect structures was discussed.

INVESTIGATIONS ON DEFECT STRUCTURE AND LIGHT-INDUCED SCATTERING OF Mg:Ho:LiNbO3 WITH VARIOUS Mg2+ CONCENTRATION

Congruent Ho 3+ (1 mol.%): LiNbO 3 crystals codoped with MgO (X mol.%, X = 1, 3, 5 and 7) were grown by the Czochralski technique. The ultraviolet-visible (UV-Vis) and infrared (IR) spectra were measured in order to analyze the defect structure of the crystals. The concentrations of Mg , Ho , Li and Nb in the crystals were carried out with an inductively coupled plasma atomic emission spectrometer. Experimental results indicates as Mg 2+ doping concentration increases in melt, the distribution coefficients of Mg and Ho ions decrease, the Li / Nb ratio in the crystals decreases first and then increases, and the absorption edge shifts to a shorter wavelength. The light-induced scattering of Mg : Ho : LiNbO 3 crystals was quantitatively scaled via the incident exposure energy. The results demonstrated that Mg (7 mol.%): Ho : LiNbO 3 crystal had the weakest light-induced scattering and the mechanism related to their defect structures was discussed.

Influence of Hf4+ ions concentration on the defect structure and exposure energy in Hf:Ho:LiNbO3

A series of Hf:Ho:LiNbO3 crystals with various levels of HfO2 doping were grown by the conventional Czochraski technique. The measurement of the Hf and Ho concentrations in the crystals was carried out with an inductively coupled plasma atomic emission spectrometer (ICP-OE/MS). The infrared (IR) spectrum was measured in order to analyze the defect structure of the crystals. The light-induced scattering was characterized quantitatively via the incident exposure energy. The results showed that the ability to resist the light-induced scattering was improved considerably with the increase in concentration of Hf4+, however, light-induced scattering resistance ability weakened as the concentration of Hf4+ surpasses the concentration to 8mol%. The relationship between the defect structures and the light-induced scattering was discussed.

Photorefractive and optical scattering properties of Zr:Fe:LiNbO3 crystals

The LiNbO3 crystal co-doped with ZrO4 and Fe2O3 has been grown with [Li]/[Nb]=0.85 and 1.20, respectively, by the Czochralski method in air atmosphere. The incident exposure energy flux threshold for the light-induced scattering was characterized to investigate the scattering properties of the crystals. Applying the results of the incident exposure energy flux threshold effect, the photorefractive properties at different laser wavelengths (473nm and 532nm) were also measured by using the typical two-wave coupling experiments. The results show that Zr:Fe:LiNbO3 crystal has a larger refractive index change, higher recording sensitivity and larger two-wave coupling gain coefficient at 473nm wavelength than those obtained at 532nm wavelength under the same experimental conditions. Moreover, the photorefractive properties decrease with the increasing [Li]/[Nb] ratios. The material of Zr:Fe:LiNbO3 crystal is a promising candidate for blue photorefractive holographic recording.

Defect structure and light‐induced scattering of Zr‐doped near‐stoichiometric Mn:Fe:LiNbO3 crystals grown by TSSG method

AbstractNear‐stoichiometric Mn:Fe:LiNbO3 crystals doped with various concentration of ZrO2 were grown by top seed solution growth (TSSG) method in the air atmosphere. The Zr concentration in the crystal was determined by inductively coupled plasma optical emission spectrometer. The defect structures were analyzed by means of ultraviolet‐visible and infrared transmittance spectra. The appearance of vibration peak at 3466 cm‐1 in infrared spectra manifested that Li/Nb ratio in crystals approached to stoichiometric proportion. The fundamental absorption edge represented continuous red‐shift which was discrepancy with congruent doped LiNbO3 crystals showed that doping ions possessed different location mechanism. The light‐induced scattering of the doped stoichiometric LiNbO3crystals were quantitatively scaled via incident exposure energy. The results demonstrated that Zr(2 mol%):Mn:Fe:LiNbO3 crystal had the weakest light‐induced scattering and the mechanism related to their defect structures was discussed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Investigation on the defect structure and light-induced scattering of LiNbO 3:Fe:Mg:Zr crystals with various Li/Nb ratios

A series of LiNbO 3:Fe:Mg:Zr single crystals with various Li/Nb ratios in the melt were grown by the Czochralski method in the air. The ultraviolet–visible and infrared transmittance spectra were measured to investigate the defect structures of these crystals. A new vibration peak of 3502 cm −1 was observed in infrared transmittance spectra. The sequence of substitution was concluded according to the spectroscopic characterization. The light-induced scattering of LiNbO 3:Fe:Mg:Zr crystals was characterized quantitatively via the incident exposure energy, and the relationship between the defect structures and light-induced scattering was discussed.

The threshold effect of incident exposure energy flux for photorefractive light-induced scattering in doped lithium niobate crystals

The threshold effect of incident exposure energy flux is proposed to measure the light-induced scattering in doped LiNbO 3 crystals. The dependences of the exposure energy flux threshold on the concentration of damage-resistant dopants as well as oxidation–reduction treatment are investigated experimentally in doped LiNbO 3 crystals. The results show that doping with damage-resistant dopants and oxidation–reduction treatment are simple and effective methods to control and optimize the photorefractive properties of doped LiNbO 3 crystals. The high signal-to-noise ratio reconstructions are also demonstrated experimentally according to the incident exposure energy flux threshold in triply-doped LiNbO 3 crystals. Comparing with the known incident intensity threshold method, the exposure energy flux threshold method is more effective for estimating the light-induced scattering of photorefractive recording materials.