A comparison of silicon oxide and nitride as host matrices on the photoluminescence from Er^(3+) ions

This paper compares the properties of silicon oxide and nitride as host matrices for Er ions. Erbium-doped silicon nitride films were deposited by a plasma-enhanced chemical-vapour deposition system.After deposition,the films were implanted with Er^3＋ at different doses.Er-doped thermal grown silicon oxide films were prepared at the same time as references.Photoluminescence features of Er^3＋ were inspected systematically.It is found that silicon nitride films are suitable for high concentration doping and the thermal quenching effect is not severe.However,a very high annealing temperature up to 1200℃ is needed to optically activate Er^3＋,which may be the main obstacle to impede the application of Er-doped silicon nitride.

1.55 μm Wavelength Operation of E_r^(3+) -Doped Optical Fiber Bistability

An all optical all fiber optical bistability operation has been realized in an all fiber cavity consisted with Er doped fiber and optical fiber loop mirrors. The experimental bistability threshold is consistent with the theory.

Absorptive Nonlinearity in Er-Doped Optical Fiber

Optical absorptive nonlinearity in Er doped optical fiber has been discussed and measured at the window wavelength 1.55 μm for optical communications firstly. It is proposed that the mechanism of this absorptive nonlinearity is the induced absorption. The first order nonlinear absorptive coefficient and the imaginary part and the complex value of the third order susceptibility at that wavelength are obtained from the measured absorptive nonlinearity.

Emission Properties of Yb^(3+)/Er^(3+) Doped TeO_2-WO_3-ZnO Glasses for Broadband Optical Amplifiers

The Yb3+/Er3+ doped TeO2-WO3-ZnO glasses were prepared. The absorption spectra, emission spectra and fluorescence lifetime of Er3+ at 1.5 um, excited by 970 nm were measured. The influence of Er2O3, Yb2O3 and OH-contents on emission properties of Er3+ at 1.5μm was investigated. The optimum doping concentrations for Er3+ and Yb3+ is around 3.34×1020 ions/cm3 and 6.63×1020 ions/cm3, respectively. The peak emission cross section is 0.83~0.87 pm2. With the increasing concentration of Yb3+, the FWHM of Er3+ emission at 1.5μm in the glass increases from 77 nm to 83 nm. The results show that Yb3+/Er3+ doped TeO2-WO3-ZnO glasses are promising candidate for Er3+-doped broadband optical amplifier.

Frequency Up-conversion Luminescence Properties and Mechanism of Tm^(3+) /Er^(3+)/Yb^(3+) Co-doped Oxyfluorogermanate Glasses

Oxyfluoride glasses were developed with composition 60GeO 2 ·10AlF 3 ·25BaF 2 ·（1.95-x）GdF 3 · 3YbF 3 ·0.05TmF 3 ·xErF 3 （x=0.02,0.05,0.08,0.11,0.14,0.17）in mole percent.Intense blue（476 nm）,green（524 and 546 nm）and red（658 nm）emissions which identified from the 1G 4 →3H 6 transition of Tm3＋and the（2H 11/2 ,4S 3/2 ）→4I 15/2 ,4F 9/2 →4I 15/2 transitions of Er3＋,respectively,were simultaneously observed under 980 nm excitation at room temperature.The results show that multicolor luminescence including white light can be adjustably tuned by changing doping concentrations of Er3＋ion or the excitation power.In addition,the energy transfer processes among Tm3＋,Er3＋and Yb3＋ions,and up-conversion mechanisms are discussed.

Photoluminescence spectroscopy of sputtering Er-doped silicon-rich silicon nitride films

Er-doped silicon-rich silicon nitride （SRN） films were deposited on silicon substrate by an RF magnetron reaction sputtering system. After high temperature annealing, the films show intense photoluminescence in both the visible and infrared regions. Besides broad-band luminescence centered at 780 nm which originates from silicon nanocrystals, resolved peaks due to transitions from all high energy levels up to 2H11/2 to the ground state of Er^3＋ are observed. Raman spectra and HRTEM measurements have been performed to investigate the structure of thefilms, and possible excitation processes are discussed.

Effects of Mo on phase structure and up-conversion emissions of Er:Al_2O_3 nanocrystals

A simple and efficient approach was presented to enhance up-conversion emissions significantly for the Er：Al2O3 nanocrystals by Mo support （Er-Mo：Al2O3） with a 976 nm laser diode excitation. Mo support had evident effects on the phase structure and up-conversion emissions for the Er：Al2O3 nanocrystals, which promoted the θ-（Al,Er）2O3 transformed to α-（Al,Er,Mo）203 phase, Compared with the Er：Al2O3, the maximal green and red up-conversion emissions intensities increased about 3×10^3 and 1.4×10^2 times for the Er-Mo：Al2O3 nanocrystals, respectively. It suggests that the enhancement of up-conversion emissions is caused by the high excited state energy transfer process from [4115/2, 3T2） state of the Er3＋-MoO2- dimer to the 4F7/2 level of E3＋.

Study on analysis of crystal structure in CeO_2 doped with Er_2O_3 or Gd_2O_3

To simulate the effects of burnable poison doping in nuclear fuel UO2,Er2O3(or Gd2O3)-doped CeO2 pellets were prepared. Changes in lattice constant and atomic disordering for CeO2 due to the Er2O3 and Gd2O3 doping were measured by means of XRD and XAFS. By the Er2O3 doping,the lattice constant decreased,and a disordering of lattice structure was induced in the samples. The doping with Er2O3 also induced the disordering of atomic arrangement around Er atoms,which was observed through the change in XAFS spectra. In contrast,the effect of Gd2O3 doping was smaller than that of Er2O3 doping. The result was discussed in terms of ionic size of dopants in CeO2 crystal.