Optical Absorption Spectra Of Er3 Research Articles

Structural and luminescence investigations of Gd3+ - Er3+ doped in lithium aluminum borate glasses using XANES and EXAFS techniques

The typical melt quenching technique was utilized to produce a possibly unique series of Gd3+ and Er3+ dual doped borate glasses with a composition of 25Li2O–5Al2O3-XGd2O3-(69.0-X)B2O3-1.0Er2O3. The amorphous nature and information on chemical bindings of the materials were validated by using fundamental characterization techniques such as X-ray diffraction, Fourier transform infrared, X-ray absorption near-edge structure, and optical screening to identify their features (absorption, excitation, and emission). The refractive index of the glasses improves from 1.5487 to 1.628 as the concentration of Gd2O3 increases. The optical absorption spectra of Er3+ doped glasses were measured from the ultraviolet (UV) through the visible (Vis) and near infrared (NIR) ranges with varying Gd2O3 concentrations in order to determine their optical properties. This luminescence was found to be predominant in photoluminescence spectra, which were obtained at an optimum doping Gd2O3 concentration of 7.5 mol%. The impact of Er3+ doping was assessed through photoluminescence, which exhibited a broad, intense NIR band at 1537 nm ascribed to the 4I13/2 → 4I15/2 transition of Er3+ ions at λEx = 486, 526, 651, and 978 nm excitation, which exhibits outstanding increased intensity with the Er3+ concentration until it reaches 1.0 mol %. A look at visible and near-infrared optical, it is observed that LAGd7.5BEr1.0 glass is a more potential candidate for photonic devices.

Judd–Ofelt analysis and physical properties of erbium modified cadmium lithium gadolinium silicate glasses

Erbium doped 50SiO2 -30Li2O- 1Gd2O3- (19 − x) CdO and x Er2O3 glass system, where (0 ≤ x ≥ 2.5), mol%, has been prepared by the conventional melt quenching technique. The physical, structural and optical properties are explained by analyzing the data obtained from X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV–Visible (UV–Vis-NIR) and photoluminescence results. X-ray powder diffraction patterns show broad peaks which conform glassy nature of the sample. FTIR spectroscopy reveals the presence of SiO4, CdO4 and Er–O vibration groups in the glass samples. The optical absorption spectra in the wavelength range of 200–2500 nm were measured and the optical band gaps, Urbach energy, Electronegativity (χ) Electron Polarizability (α°), and Optical basicity (˄) were determined. The optical absorption spectra of Er3+ ions in these glasses show eleven bands and are assigned to the transitions from ground state to excited levels. It was found that the optical band gap increases from 3.19 to 3.51 eV with the increase in Er2O3 concentration. The strong sharp peak belongs to Er+3 emission is investigated in photoluminescence spectra at ordinary condition (1 atm. and at room temperature). It excites by wavelength of 385 nm and gives pale green color at 559 nm. Judd–Ofelt theory has been used to analyze the spectra arising from erbium ions doped 50 SiO2 -30 Li2O- 1Gd2O3- (19 − x) CdO and x Er2O3. The intensity parameters Ω2,4,6 of the present complex and lifetimes of selected levels are theoretically calculated as well.

Characterization and optical properties of erbium oxide doped ZnO–SLS glass for potential optical and optoelectronic materials

Erbium doped ZnO–SLS (soda lime silica) glass system have been prepared by the conventional melt quenching technique. The physical, structural and optical properties are explained by analysing the data obtained from Energy Dispersive X-ray Fluorescence (EDXRF), density (ρ), molar volume (V m), X-ray diffraction (XRD), fourier transform infra-red (FTIR) and UV-visible (UV-Vis) results. The measured physical parameters like density and molar volume are found to vary linearly and exponentially with increasing Er2O3 content, respectively. X-ray powder diffractrogram show broad peaks which conforms glassy nature of the sample. FTIR spectroscopy reveals the presence of SiO4, ZnO4 and Er–O vibration groups in the glass samples. The optical absorption spectra were measured in the wavelength range from 300 to 800 nm and the optical band gaps were determined. The optical absorption spectra of Er3+ ions in these glasses show three bands and are assigned to the transitions level. It was found that the optical band gap decreases from 3.083 to 3.037 eV with an increase in Er2O3 concentration.

Optical and Photoluminescence Properties of Erbium-Doped Chalcogenide Glasses (GeGaS:Er)

We have examined the optical and photoluminescence (PL) properties of Er3+-doped GeGaS glasses of near-stoichiometric composition Ge28Ga6.2S65.3:Er0.5. We have also used powdered samples of various mean sizes (L) to examine the dependence of the 1.54 -mum PL emission spectrum and the PL decay time on the average sample size. Optical absorption spectra of Er3+ ions arising from transitions between different energy manifolds, such as 4 I15 /2 -4 I13/2,4 I15 /2 -4 I11 /2 , etc., have been used to extract Omega2, Omega4, and Omega6 values using the Judd-Ofelt analysis and a Judd-Ofelt radiative lifetime TJO = 2.6 ms for the 4 I13 / 2 -4 I15 / 2 transition. The PL emission spectra and the decay time have been found to depend on the mean sample size. The spectra are broader and the decay times are longer for larger sample sizes, due to photon trapping occurring in the sample. The extrapolated decay time to zero particle size yields a decay time that matches the Judd-Ofelt radiative lifetime almost perfectly, and confirms the argument that the true PL lifetime needs to be measured in fine powders to avoid reabsorption effects. We have estimated the maximum emission cross section as 15.5 X 10-21 cm2.

Electron trapping center and SnO2-doping mechanism of indium tin oxide

Indium tin oxide (ITO) and Er3+-doped ITO powders were prepared by a conventional ceramic method. The density of ITO powders and optical absorption spectra of Er3+ ions in Er3+-doped ITO were measured as a function of the SnO2 doping level. The results obtained were discussed in terms of the trapping center for immobile electrons in ITO. Observed densities of ITO powders were in good agreement with those calculated from their lattice parameters, assuming that the immobile electrons were trapped at the excess interstitial oxygen. The optical absorption spectra of Er3+-doped ITO indicated that some In3+ ions in ITO were surrounded by 7 and/or 8 oxygen ions; the increase in the coordination number of In3+ from 6 in In2O3 to 7 and/or 8 in ITO must be caused by the introduction of excess interstitial oxygen into the quasi-anion site in the C-typerare-earth lattice upon SnO2 doping. It was concluded that the immobile electrons in ITO are trapped at the excess interstitial oxygen, and that the mechanism of conduction carrier generation and compensation upon SnO2 doping into In2O3 can be expressed by the defect equation, 2SnO2?2SnIn·+2(1-z)e′+zOi′′+3OO×+(1-z)/2O2.

Optical absorption intensities and quantum counter action of Er3+ in yttrium gallium garnet

The intensities of optical absorption spectra of Er3+ in single crystals of yttrium gallium garnet at 700 °K have been shown to fit Judd's theory of 4f-4f transitions with the following parameters: T2 = 144 × 10-21 s, T4 = 112 × 10-21 s, T6 = 142 × 10-21 s. These have been used to estimate Einstein coefficients useful in a discussion of the quantum efficiency of the fluorescence from the 4S3/2 state, and the efficiency of infra-red quantum counter action in the material. For pure spontaneous radiation an efficiency of 71% for transitions to the 4I15/2 ground state is expected. The quantum efficiency has also been directly measured and a value of 12% was obtained. This is lower owing to competing phonon processes. Using the experimental value for the quantum efficiency, and the above values of T, a theoretical photon gain for quantum counter action of 055 × 10-8 has been calculated.