Grain refining of Er added to Ti-22Al-25Nb alloy and morphology of erbium precipitates

In order to investigate the effect of erbium （Er） on the microstructure of orthorhombic Ti2A1Nb-based alloys, four testing alloys were prepared by adding differ- ent contents of the rare earth metal Er to Ti-22A1-25Nb alloy and optical microscopy, X-ray diffraction, scanning electron microscopy, electron probe microanalysis, energy- dispersive spectrometry, and transmission electron microscopy were used. The results show that the addition of Er is capable of grain refining and the refinement effect is more obvious with increasing content of Er. The Er203 dispersoids formed by internal oxidation and A13Er com- pound particles are observed in Er-doped alloys and the number of Er precipitates is increased with increasing Er addition. It is likely that the solubility of Er in the Ti2A1Nb alloy is very low and Er precipitates tend to segregate at grain boundaries, which together with the surface activity of rare earth elements is supposed to decrease the prior B2 grain size of Ti-22A1-25Nb alloy effectively.

Fabrication of Erbium and Ytterbium Co-Doped Tantalum-Oxide Thin Films Using Radio-Frequency Co-Sputtering

An erbium and ytterbium co-doped tantalum-oxide (Ta2 O5:Er, Yb) thin film was fabricated using a simple co-sputtering method for the first time, and its photoluminescence (PL) spectrum was evaluated. Energy transfers between Er3+ and Yb3+ in the Ta2 O5:Er, Yb co-sputtered thin film were discussed by comparing between PL spectra of the Ta2 O5:Er, Yb film and Ta2 O5:Er or Ta2 O5:Yb films reported in our previous works. Such a Ta2 O5:Er, Yb co-sputtered film can be used as a high-refractive- index and light-emitting material of a multilayered photonic crystal that can be applied to a novel light-emitting device, and it will also be used as a multi-functional coating film having both anti-reflection and down-conversion effects for realizing a high-efficiency silicon solar cell.

Microstructure and mechanical properties of Al-Mg-Mn alloy with erbium

The effect of trace element Er on the microstructure and properties of Al-6Mg-0.7Mn-0.1Cr-0.15Ti alloy was investigated. The results show that the ultimate room-temperature and high-temperature strength sof the alloy have not increased obviously with the addition of erbium, but the uniform elongation of alloys decreases from 9% and 27.5% to 5.5% and 22.5%, respectively. The reason is that the addition of Er will first react with Ti, Cr to form Al20Ti2Er, Al8Cr4Er phases. The precipitation strengthening makes up the weakening of grain refinement strengthening. During deformation, the primary Al(TiCr)Er and Al3Er particles fracture first and act as the microcrack sources because of the stress concentration.

Dynamics of erbium-doped fibre laser with optical delay feedback and chaotic synchronization

The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.

Sorption Behavior and Mechanism of D113 Resin for Erbium

The sorption behavior and mechanism of a novel macroporous weak acid resin(D113 resin) for Er(Ⅲ) were investigated. The optimal sorption condition of D113 resin for Er(Ⅲ) was pH 6.42 in HAc-NaAc medium. The statically saturated sorption capacity was 272 mg·g-1 at 298 K in HAc-NaAc medium. The Er(Ⅲ) adsorbed on D113 resin could be reductively eluted by the mixed solution of HCl and NaCl. The elution percentage could reach 100%. The resin could be regenerated and reused without apparent decrease of sorption capacity. The apparent sorption rate constant was k298=1.98×10-5 s-1. The apparent activation energy was 8.60 kJ·mol-1. The sorption behavior of D113 resin for Er(Ⅲ) obeyed the Freundlich isotherm and Langmuir isotherm. The sorption parameters of thermodynamics were ΔH=44.0 kJ·mol-1, ΔS=223 J·mol-1·K-1, ΔG298 K=-22.3 kJ·mol-1, respectively. The molar coordination ratio of the functional group of D113 resin to Er(Ⅲ) was 3∶1. The sorption mechanism of D113 resin for Er(Ⅲ) was examined using chemical method and IR spectrometry.

Adsorption of erbium(Ⅲ) on D113-Ⅲ resin from aqueous solutions: batch and column studies

The adsorption and desorption behaviors of Er(Ⅲ) ion on D113-Ⅲ resin were investigated.Batch adsorption studies were carried out with various Er(Ⅲ) ion concentrations,pH,contact time and temperature,indicating that D113-Ⅲ resin could adsorb Er(Ⅲ) ion effectively from aqueous solution.The loading of Er(Ⅲ) ion onto D113-Ⅲ resin increased with increasing the initial concentration.The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.45 to 6.75.In the batch s...

Flattening Spectrum of a Broadband and Wavelength Stable Erbium Doped Superfluorescent Fiber Source

A technique is used to design the spectra in erbium doped superfluorescent fiber source experimentally and theoretically.In an erbium doped fiber with a 10m length and 300ppm concentration,a line width of about 42nm and high mean wavelength stability(<0.lppm/K,<0.2ppm/mW)were obtained by means of a suitable population distribution,and adjusting the ratio of backward to forward pump power.Also,its thermal characteristic is studied.These results will improve the performance of fiber optical gyroscope and fiber sensors,and will be applied in erbium doped fiber amplifier with flattening gain.

An experiment of dynamical behaviours in an erbium-doped fibre-ring laser with loss modulation

This paper reports a systematic experimental investigation on the dynamics in the low-frequency region in an erbium-doped fibre-ring laser with loss modulation. A rich variety of bifurcation is analyzed through the bifurcation diagram and structured with the concept of the winding numbers. The coexistence of multiple attractors and the crisis that appear in the saddle-node bifurcations, and an interesting structure of bifurcation which is similar to the bifurcations in high-frequency range, have been observed.

Stable and High OSNR Compound Linear-Cavity Single-Longitudinal-Mode Erbium-Doped Silica Fiber Laser Based on an Asymmetric Four-Cavity Structure

We propose a stable and high optical signal-to-noise ratio(OSNR)compound linear-cavity single-longitudinal-mode(SLM)erbium-doped silica fiber laser.It consists of three uniform fiber Bragg gratings(FBGs)and two fiber couplers to form a simple asymmetric four-cavity structure to select the longitudinal mode.The stable SLM operation at the wavelength of 1544.053 nm with a 3 dB bandwidth of 0.014 nm and an OSNR of~60 dB was verified experimentally.Under laboratory conditions,a power fluctuation performance of less than 0.05 dB for 5 h and wavelength variation of less than 0.01 nm for about 150 min is demonstrated.Finally,the characteristic of laser output power as a function of pump power is investigated.The proposed system provides a simple and cost-effective approach to realize a stable SLM fiber laser.

A Switchable Multi-wavelength Erbium-Doped Photonic Crystal Fiber Laser with Linear Cavity Configuration

A switchable multi-wavelength erbium-doped photonic crystal fiber laser with a linear cavity configuration based on a Sagnac loop mirror is proposed and demonstrated experimentally.The laser is based on saturated spectral hole burning and the polarization hole burning effects can be switched among single-wavelength,dual-wavelength,triple-wavelength and quadruple-wavelength outputs at room temperature.The wavelength period of the output spectrum is easily varied by using polarization maintaining fibers of different lengths.The proposed fiber laser has a signal-to-noise ratio of higher than 30 dB and achieves a low threshold power of 37 mW.The power fluctuations of the lasing lines are less than 0.54 dB,1.7 dB and 2.9 dB when the laser operates at single-wavelength,dual-wavelength and triple-wavelength for one hour.

Stable single longitudinal mode erbium-doped silica fiber laser based on an asymmetric linear three-cavity structure

We present a stable linear-cavity single longitudinal mode （SLM） erbium-doped silica fiber laser. It consists of four fiber Bragg gratings （FBGs） directly written in a section of photosensitive erbium-doped fiber （EDF） to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio （OSNR） of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer （OSA） for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser.

Optical Pulse Compression Based on High-doped Erbium Fiber Amplifier and Standard Single-mode Fiber

Proposed is a novel optical pulse compression technique based on high-doped erbium fiber amplifier and standard single-mode fiber(SMF). We used the amplifier with the erbium ion concentration of 6.3×10-3 to amplify a hyperbolic secant pulse from a regeneratively mode-locked fiber laser. The central wavelength, pulsewidth and peak power of the pulse are 1 550 nm, 12.5 ps and 3 mW, respectively. Then the amplified pulse with peak power level corresponding to a higher-order soliton is compressed when it propagates through a 3-km-long single-mode fiber. Studied are the compressed pulses under different pump powers and fiber lengths. The results show that it can get a narrower pulse, and solve the difficulty that pulses at low power can not be compressed directly in the fiber. And the construct is compact.

Transition state to mode locking in a passively mode-locked erbium-doped fibre ring laser

The transition state between the continuous wave region and the mode-locked region in a passively mode-locked erbium-doped fibre ring laser has been experimentally observed by utilizing the nonlinear polarization rotation technique. When the pump power reaches the mode-locked threshold, the metastable pulse train with a tunable repetition rate is obtained in the transition from the continuous wave state to the passive mode-locked state via proper adjustment of the polarization controller. A simpie model has been established to explain the experimental observation.

Experimental investigation on chaos generation in erbium-doped fiber single-ring lasers

In this paper,the chaotic behaviors in an erbium-doped fiber（EDF） single-ring laser（EDFSRL） are investigated experimentally by using the loss modulation method.An electro-optic modulator（EOM） made of LiNbO 3 crystal is added to the system.Thus,by changing the modulation voltage and the modulation frequency of the EOM,the freedom of the EDFSRL system is increased.The chaotic characteristics of the system are studied by observing the time series and the power spectra.The experimental results indicate that the erbium-doped fiber single-ring laser system can enter into chaos states through period-doubling bifurcation and intermittency routes.

Ring-Opening Polymerization of ε-Caprolactone Catalyzed by Diisopropylamido Bis(methylcyclopentadienyl) Erbium Tetrahydrofuranate Complex

Ring-opening polymerization of Ε-caprolactone was successfully carried out by diisopropylamido bis (methylcyclopentadienyl) erbium as the catalyst. It is found that organoerbium amide is a very active catalyst for Ε-caprolactone ring-opening polymerization. The activity increases with the increasing of polymerization temperature. Under certain conditions, the polymerization system shows a living characteristic.

Synthesis and Structures of Three Erbium(Ⅲ) Dicarboxylate Coordination Polymers

Three polymeric erbium(Ⅲ) complexes [Er(oba)(Hoba)(H 2O) 2]H 2O (A),[Er 2(oba) 3(H 2O) 4] (B), [Er 2(oba) 3(2,2′ bpy) 2] (C) (H 2oba=4,4′ oxybis(benzoic acid), 2,2′ bpy = 2,2′ bipyridine) were hydrothermally synthesized by altering the metal/carboxylate ratios or in the presence of an additional chelate 2,2′ bpy ligand, and characterized by single crystal X ray diffraction. The results show that different metal/carboxylate ratios can influence the polymeric structures and the presence of 2,2′ bpy ligand alters the topology of the framework from two dimensional to three dimensional.

Synthesis and Crystal Structure of Bis(tert-butyl-cyclopentadienyl)Erbium Ethoxide, (t-BuCp)_2ErOEt

The formation of ( t BuCp) 2ErOEt was discussed. Its single crystal structure was determined by X ray diffraction. The crystal is monoclinic, P 2(1)/ c space group, a =1.0191(2), b =1.6203(5), c =1.2118(3) nm, β =102.960(10)°, V =1.9500 (nm 3), Z =2, D c=1.566 mg·m -3 , R =0.0450, R w=0.1363. The complex is monomeric and solvent free in the solid state. The erbium ion is coordinated by two tert butyl cyclopentadienyl rings and one oxygen atom of ethoxy group to form a seven coordinated complex.

Rutherford Backscattering and Luminescence Studies Erbium Implanted Silicon

Annealing behavior of Er-implanted Si was studied by Rutherford backscattering (RBS) and photoluminescence (PL). RBS data show that the recrystallization process of damaged layers is accompanied by migration of Er atoms toward surface during annealing. After annealing the depth of the Er concentration peak corresponds to the depth of the residual damage layer. Er atoms in Si mainly occupy nonsubstitution sites. The presence of a lot of interstitial Er atoms in Si retards the recrystallization process of damaged layers. The 1.546 μm PL peak related to Er was observed at 77K.

Synthesis, Characterization, Thermal Decomposition Mechanism and Non-Isothermal Kinetics of Salicylaldehyde Salicylhydrazone and Its Complex of Erbium(Ⅲ)

The salicylaldehyde salicylhydrazone and its complex of Er(Ⅲ) were synthesized. The formulae K·4H_2O(HL=[C_(14)H_(10)N_2O_3]^(2-), the bivalent form of the salicylaldehyde salicylhydrazone) were determined by elemental analysis and EDTA volumetric analysis. Molar conductance, IR, UV and X-ray power diffraction were carried out for the characterizations of the complex and the ligand. There are two stable five-numbered and six-numbered circles in the complex. The thermal decompositions of the ligand and the complex with the kinetic study are carried out by non-isothermal thermogravimetry. The stages of the decompositions were identified by TG-DTG curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by the corresponding kinetic parameters.The activation energy value of the main step decomposition are also calculated by Kissinger′s method and Ozawa′s method.

Synthesis and Structure of a Novel Tetranuclear Erbium( Ⅲ) Complex with α-Alanine[Er_4(HAla)_6·(μ_3-OH)_4(H_2O)_8](ClO_4)_8·3H_2O

The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal crystallizes in a triclinic system, space group P1 with a= 1.306 3(2) nm , b=1.319 4(4) nm, c=1.950 2(4) nm, α=90.597(14)°, β= 93.998(11)° , γ=94.093(13)°, V=3.344 1(12) nm3, Z=2, the final R indices are R 1= 0.065 4 , wR 2=0.126 2 respectively. The complex contains a novel tetranuclear cluster cation with four Er 3+ ions connected by four μ 3OH ions and six bridging carboxyl groups. Each erbium ion is coordinated by three μ 3OH, three carboxylic oxygen atoms from three αalanine and two oxygen atoms from water molecules, forming a squareantiprismatic coordination polyhedron.