Influence of vapor transport equilibration on spectroscopic properties of Er:LiNbO3 crystal heavily codoped with MgO

Abstract

Articles you may be interested inSpectroscopic and upconversion properties of erbium-doped potassium lithium tantalate niobate crystals under 800 nm femtosecond laser excitation J. Appl. Phys. 108, 043520 (2010); 10.1063/1.3475511Judd-Ofelt analysis of spectroscopic property of Er 3 + in congruent and near-stoichiometric Zn ∕ Er -codoped Li Nb O 3 crystals Z-cut MgO heavily codoped ͑6 mol % ͒ Er͑0.4 mol % ͒ : LiNbO 3 crystals were thermally treated at 1110 and 1120°C over 100, 120, and 220 h using vapor transport equilibration ͑VTE͒ technique. Visible and infrared-absorption and x-ray powder diffraction have been used to characterize their spectral, spectroscopic, and crystalline phase characteristics in comparison with the as-grown crystal. The experimental results show that VTE treatment results in the reduction of background absorption and 4 -5-nm blueshift of the optical-absorption edge, qualitatively showing that these crystals have been brought closer to stoichiometric composition. The VTE procedure also results in remarkable Er 3+ absorption changes. These spectroscopic changes imply that the VTE treatment may result in the formation of ErNbO 4 precipitates in all VTE crystals. In addition, the VTE treatment also results in substantial spectral changes with respect to OH − absorption. These OH − spectral changes are explained from the viewpoint of VTE-induced site-occupancy alterations of intrinsic and extrinsic defects. Based upon the measured absorption spectra, the influences of VTE treatment on the Er 3+ spectroscopic parameters were studied by using the Judd-Ofelt ͑JO͒ theory. The theoretical results show that VTE treatment has a little influence on the branch ratio, and a substantial influence on JO parameters and electron transition probability because of the phase transformation with respect to Er 3+ . The VTE treatment results in the increase of the JO parameters by more than 50% and theoretical radiative lifetime by 50%-120%.

X‐Ray, Micro‐Raman, Optical Absorption/Emission Studies of ErNbO4 Grown by Vapor Transport Equilibration

“…The coexistence of the Er 31 ions as LiNbO 3 and ErNbO 4 phases also results in considerable spectral changes of the emissions at 1.5 mm as shown in Figs. 6 and 7, where the polarized infrared emission spectra of the bulk and locally Er-doped VTE crystal in the wavelength range of 1450-1650 nm are shown, respectively.…”

“…T he vapor transport equilibration (VTE) technique has been proved to be a practical and effective method of altering the Li/Nb or Li/Ta ratio in a LiNbO 3 or LiTaO 3 crystal. Recently, this technique has been applied to bulk‐doped (MgO) Er(/Yb):LiNbO 3 1–3 . It was found that when the total doping level of all external dopants is <∼1.0 mol%, the VTE treatment under the often adopted condition of 1100°C/∼100 h cannot induce precipitation of the crystal, and the crystal after the VTE treatment reveals some spectral characteristics favorable for integrated opto‐electronics application.…”

“…Recently, this technique has been applied to bulk-doped (MgO) Er (/Yb):LiNbO 3 . [1][2][3] It was found that when the total doping level of all external dopants is oB1.0 mol%, the VTE treatment under the often adopted condition of 11001C/B100 h cannot induce precipitation of the crystal, and the crystal after the VTE treatment reveals some spectral characteristics favorable for integrated opto-electronics application. On the other hand, when the doping level of the external dopants is higher than 1.0 mol%, the VTE treatment may induce formation of ErNbO 4 or YbNbO 4 precipitates in the bulk-doped (MgO) Er(/Yb):LiNbO 3 crystals.…”

Spectroscopic analysis of Er3+ transition in Mg/Er-codoped LiNbO3 crystal

“…But Zhong et al [16] showed that LiNbO 3 doped with about 5 mol% or more MgO exhibits a remarkable reduced photo-refractive response compared with pure. Mg/Er-codoped LiNbO 3 crystal is attracting attention [17][18][19]. Fortunately, recent literature [20,21] has reported luminescence enhancement effect in Er:LiNbO 3 crystals codoped with MgO.…”

Emission and Absorption Cross Sections at 810 and 860 nm Bands of Er3+ in LiNbO3 Crystal

“…Up to date, the Er 3+ spectroscopic knowledge tends to be complete. Researchers have reported various aspects of Er 3+ spectroscopic properties such as absorption and emission (including upconversion) characteristics, [10][11][12][13][14][15][16][17][18][19][20] Judd-Ofelt theoretical data, [21][22][23][24][25][26] site occupation in lattice, [27][28][29][30][31] and absorption and emission cross-section characteristics of Er 3+ ion in both the bulk material 6,[32][33][34][35][36] and waveguide structure. [37][38][39][40][41][42][43] In the aspect of absorption and emission cross section, the knowledge is not complete yet.…”