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 ...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.展开更多
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 ...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.展开更多
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 statical...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.展开更多
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...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 system,the D113-Ⅲ resin exhibited the highest Er(Ⅲ) ion uptake as 250 mg/g at 298 K,at an initial pH value of 6.04,calculated from the Langmuir isotherm model.The adsorption kinetics was in agreement with Lagergren-first-order kinetics among the Lagergren-first-order model,pseudo-second-order model,liquid film diffusion model and intraparticle diffusion model.The adsorption data gave good fits with Langmuir isotherms.The thermodynamic parameters such as △G,which were all negative,indicated that the adsorption of Er(Ⅲ) ion onto D113-Ⅲ resin was spontaneous and the positive value of △H showed that the adsorption was endothermic in nature.Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design.Er(Ⅲ) ion could be eluted by using the 4.0 mol/L HCl solution.The characterization of both before and after adsorption of Er(Ⅲ) ion on D113-Ⅲ resin was undertaken with IR spectroscopic technique.Moreover,the surface characterization of D113-Ⅲ resin was described by scanning electron micrographs(SEM).展开更多
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 a...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.展开更多
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 ...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.展开更多
The salicylaldehyde salicylhydrazone and its complex of Er（Ⅲ） were synthesized. The formulae K·4H2O(HL=[C14H10N2O3]2-, the bivalent form of the salicylaldehyde salicylhydrazone) were determined by elemental an...The salicylaldehyde salicylhydrazone and its complex of Er（Ⅲ） were synthesized. The formulae K·4H2O(HL=[C14H10N2O3]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.展开更多
The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal is rhombohedral, space group R3 with a=1.947 0(3) nm, b=1.947 0(3) nm, c=1.768 3(3) n...The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal is rhombohedral, space group R3 with a=1.947 0(3) nm, b=1.947 0(3) nm, c=1.768 3(3) nm, α=90°, β=90°, γ=120°, V=5.805(2) nm3, Z=3 , the final R value is 0.051 2. The complex contains a novel tetranuclear 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 Lproline, and two or one oxygen atoms from water molecules.展开更多
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...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.展开更多
Bidirectional EDFAs(Bi-EDFAs)featuring bidirectional signal input are theoreticallystudied.Gain and noise performances of Bi-EDFAs are analysed numerically and comparedwith that of other optical amplifiers.Application...Bidirectional EDFAs(Bi-EDFAs)featuring bidirectional signal input are theoreticallystudied.Gain and noise performances of Bi-EDFAs are analysed numerically and comparedwith that of other optical amplifiers.Applications of Bi-EDFAs in fiber networks and otherfields are considered.展开更多
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 spec...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.展开更多
A mode-locked erbium-doped fiber laser (EDFL) is demonstrated using a highly concentrated erbium-doped fiber (EDF) as the gain medium in a ring configuration with and without a saturable absorber (SA).Without the SA,t...A mode-locked erbium-doped fiber laser (EDFL) is demonstrated using a highly concentrated erbium-doped fiber (EDF) as the gain medium in a ring configuration with and without a saturable absorber (SA).Without the SA,the proposed laser generates soliton pulses with a repetition rate of 12 MHz,pulse width of 1.11 ps and energy pulse of 1.6pJ.By incorporating SA in the ring cavity,the optical output of the laser changes from soliton to stretched pulses due to the slight change in the group velocity dispersion.With the SA,a cleaner pulse is obtained with a repetition rate of 11.3 MHz,a pulse width of 0.58ps and a pulse energy of 2.3pJ.展开更多
We demonstrate a simple,compact and low cost Q-switched erbium-doped fiber laser(EDFL)using single-wall carbon nanotubes(CNTs)as a saturable absorber for possible applications in metrology,sensing,and medical diagnost...We demonstrate a simple,compact and low cost Q-switched erbium-doped fiber laser(EDFL)using single-wall carbon nanotubes(CNTs)as a saturable absorber for possible applications in metrology,sensing,and medical diagnostics.The EDFL operates at around 1560 nm with repetition rates of 16.1 kHz and 6.4 kHz with saturable absorbers SA1 and SA2 at a pump power of 120 mW.The absorbers are constructed by optically driven deposition and normal deposition techniques.It is observed that the optical deposition method produces a Q-switched EDFL with a lower threshold of 70 mW and better Q-switching performance compared to that of the normal deposition method.The EDFL also has pulse energy of 90.3 nJ and pulse width of 11.6μs at 120 mW pump power.展开更多
Based on theoretical and experimental studies on the optical properties of long-period gratings(LPGs),an erbium doped fiber amplifier(EDFA)gain equalizer was fabricated by writing three long period gratings with desig...Based on theoretical and experimental studies on the optical properties of long-period gratings(LPGs),an erbium doped fiber amplifier(EDFA)gain equalizer was fabricated by writing three long period gratings with designed properties in hydrogen-loaded standard single-mode fibers.The LPGs were written by a KrF excimer laser at 248 nm with amplitude masks.The gain variation of±3dB in the EDFA is reduced to±0.3 dB with a bandwidth of 30 nm and the total insertion loss of the device is less than 0.3 dB.展开更多
Erbium silicide nanoislands on Si(001)surface are fabricated by novel multiple depositions and annealing treatments method.The morphological investigations determine that the islands could grow with stable square shap...Erbium silicide nanoislands on Si(001)surface are fabricated by novel multiple depositions and annealing treatments method.The morphological investigations determine that the islands could grow with stable square shapes rather than the shape transformation exhibited in the traditional single time evaporation growth.Size distributions analyses further elucidate the effect of multiple depositions and annealing treatments on the nanoisland growth.It is suggested that strain relaxation and static coMescence play important roles in the cyclic growth.Specifically,after 15 times of the cycles,the larger islands are found to undergo the Ostwald ripening,which make the shape of nanoislands irregular.This gives us the direction to adjust the growth parameters to control the island morphology.Furthermore,the crystalline structure of the Er silicide nanoislands is efficiently characterized by grazing incidence synchrotron x-ray diffraction.展开更多
Ring opening polymerization of ε caprolactone was successfully carried out by diisopropylamido bis(methylcyclopentadienyl) erbium as catalyst. It is found that organoerbium amide is a very active catalyst for ε capr...Ring opening polymerization of ε caprolactone was successfully carried out by diisopropylamido bis(methylcyclopentadienyl) erbium as 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.展开更多
The title complex [ErY（Gly）<sub>6</sub>（H<sub>2</sub>O）4]（ClO<sub>4</sub>）<sub>6</sub>·51H<sub>2</sub>O has been synthesized.Its crystal structure...The title complex [ErY（Gly）<sub>6</sub>（H<sub>2</sub>O）4]（ClO<sub>4</sub>）<sub>6</sub>·51H<sub>2</sub>O has been synthesized.Its crystal structure has beendetermined by X-ray diffraction method.The crystal is triclinic with space group P.The unit cell parametersare as follows:a=1.1518（4） nm,b=1.4105（7） nm,c=1.5530（6） nm,α=96.61（3）°,β=102.74（3）°,γ=105.70（3）°,V=2.3277（17） nm<sup>3</sup>,Z=2,D<sub>calc</sub>=2.091 g/cm<sup>3</sup>.The structure has been refined to a final R of0.0785.The crystal-is an infinite chain complex,in which four carboxyl groups from glycine molecules bridge theEr<sup>3+</sup> and Y<sup>3+</sup> ions,and the other two carboxyl groups bridge two adjacent Er<sup>3+</sup> or Y<sup>3+</sup> ions.展开更多
文摘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.
基金supported by the Research and Development Program of National Advance and High Technology (Nos. 2006AA03A207 and 2007AA032514)
文摘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.
基金the Zhejiang Provincial Natural Science Foundation of China (Y404279)
文摘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.
基金supported by the Analysis Project under Zhejiang Provincial Scientific and Technological Research Planning (2008F70059)Zhejiang University Graduate Business Research Innovation Fund
文摘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 system,the D113-Ⅲ resin exhibited the highest Er(Ⅲ) ion uptake as 250 mg/g at 298 K,at an initial pH value of 6.04,calculated from the Langmuir isotherm model.The adsorption kinetics was in agreement with Lagergren-first-order kinetics among the Lagergren-first-order model,pseudo-second-order model,liquid film diffusion model and intraparticle diffusion model.The adsorption data gave good fits with Langmuir isotherms.The thermodynamic parameters such as △G,which were all negative,indicated that the adsorption of Er(Ⅲ) ion onto D113-Ⅲ resin was spontaneous and the positive value of △H showed that the adsorption was endothermic in nature.Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design.Er(Ⅲ) ion could be eluted by using the 4.0 mol/L HCl solution.The characterization of both before and after adsorption of Er(Ⅲ) ion on D113-Ⅲ resin was undertaken with IR spectroscopic technique.Moreover,the surface characterization of D113-Ⅲ resin was described by scanning electron micrographs(SEM).
基金Supported by the National Natural Science Foundation of China under Grand No.19674053.
文摘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.
基金Supported by the National Natural Science Foundation of China(61077069,61107094)the Fundamental Research Funds for the Central Universities(2011YJS202,2011JBM001)。
文摘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.
文摘The salicylaldehyde salicylhydrazone and its complex of Er（Ⅲ） were synthesized. The formulae K·4H2O(HL=[C14H10N2O3]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.
基金Supported by the National Key Project of Fundamental Research and the National Natural Science Foundation ofChina(No.29771001,
文摘The title complex was synthesized in an aqueous solution and its crystal structure was determined by Xray diffraction. The crystal is rhombohedral, space group R3 with a=1.947 0(3) nm, b=1.947 0(3) nm, c=1.768 3(3) nm, α=90°, β=90°, γ=120°, V=5.805(2) nm3, Z=3 , the final R value is 0.051 2. The complex contains a novel tetranuclear 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 Lproline, and two or one oxygen atoms from water molecules.
基金Supported by the National Key Project of Fundamental Research and the National Natural Science Foundation ofChina(No.29771001,
文摘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.
基金a major project of the 8th Five-Year Plan of China.
文摘Bidirectional EDFAs(Bi-EDFAs)featuring bidirectional signal input are theoreticallystudied.Gain and noise performances of Bi-EDFAs are analysed numerically and comparedwith that of other optical amplifiers.Applications of Bi-EDFAs in fiber networks and otherfields are considered.
基金Supported in part by the Double Hundred Project of Shenzhen under Grant No 001096.
文摘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.
基金Supported by the Ministry of Higher Education under PRGS under Grant No PR003-2011AHIRG under Grant No HIR-MOHE D000009-16001.
文摘A mode-locked erbium-doped fiber laser (EDFL) is demonstrated using a highly concentrated erbium-doped fiber (EDF) as the gain medium in a ring configuration with and without a saturable absorber (SA).Without the SA,the proposed laser generates soliton pulses with a repetition rate of 12 MHz,pulse width of 1.11 ps and energy pulse of 1.6pJ.By incorporating SA in the ring cavity,the optical output of the laser changes from soliton to stretched pulses due to the slight change in the group velocity dispersion.With the SA,a cleaner pulse is obtained with a repetition rate of 11.3 MHz,a pulse width of 0.58ps and a pulse energy of 2.3pJ.
基金Supported by University of Malaya PPP under Grant No PV029/2011B.
文摘We demonstrate a simple,compact and low cost Q-switched erbium-doped fiber laser(EDFL)using single-wall carbon nanotubes(CNTs)as a saturable absorber for possible applications in metrology,sensing,and medical diagnostics.The EDFL operates at around 1560 nm with repetition rates of 16.1 kHz and 6.4 kHz with saturable absorbers SA1 and SA2 at a pump power of 120 mW.The absorbers are constructed by optically driven deposition and normal deposition techniques.It is observed that the optical deposition method produces a Q-switched EDFL with a lower threshold of 70 mW and better Q-switching performance compared to that of the normal deposition method.The EDFL also has pulse energy of 90.3 nJ and pulse width of 11.6μs at 120 mW pump power.
基金Supported by the National Natural Science Foundation of China under Grant No.69777010,the National 863 High Technology Project of China,and the Paper Publication Foundation of Northern Jiaotong University.
文摘Based on theoretical and experimental studies on the optical properties of long-period gratings(LPGs),an erbium doped fiber amplifier(EDFA)gain equalizer was fabricated by writing three long period gratings with designed properties in hydrogen-loaded standard single-mode fibers.The LPGs were written by a KrF excimer laser at 248 nm with amplitude masks.The gain variation of±3dB in the EDFA is reduced to±0.3 dB with a bandwidth of 30 nm and the total insertion loss of the device is less than 0.3 dB.
基金Supported by the National Basic Research Program of China under Grant No 2006CB921300the Natural Science Foundation of Shanghai Science and Technology Committee under Grant No 08ZR1401700Shanghai Postdoctoral Sustentation Fund under Grant No 10R21416600.
文摘Erbium silicide nanoislands on Si(001)surface are fabricated by novel multiple depositions and annealing treatments method.The morphological investigations determine that the islands could grow with stable square shapes rather than the shape transformation exhibited in the traditional single time evaporation growth.Size distributions analyses further elucidate the effect of multiple depositions and annealing treatments on the nanoisland growth.It is suggested that strain relaxation and static coMescence play important roles in the cyclic growth.Specifically,after 15 times of the cycles,the larger islands are found to undergo the Ostwald ripening,which make the shape of nanoislands irregular.This gives us the direction to adjust the growth parameters to control the island morphology.Furthermore,the crystalline structure of the Er silicide nanoislands is efficiently characterized by grazing incidence synchrotron x-ray diffraction.
文摘Ring opening polymerization of ε caprolactone was successfully carried out by diisopropylamido bis(methylcyclopentadienyl) erbium as 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.
基金The Project supported by the National Natural Science Foundation of China
文摘The title complex [ErY（Gly）<sub>6</sub>（H<sub>2</sub>O）4]（ClO<sub>4</sub>）<sub>6</sub>·51H<sub>2</sub>O has been synthesized.Its crystal structure has beendetermined by X-ray diffraction method.The crystal is triclinic with space group P.The unit cell parametersare as follows:a=1.1518（4） nm,b=1.4105（7） nm,c=1.5530（6） nm,α=96.61（3）°,β=102.74（3）°,γ=105.70（3）°,V=2.3277（17） nm<sup>3</sup>,Z=2,D<sub>calc</sub>=2.091 g/cm<sup>3</sup>.The structure has been refined to a final R of0.0785.The crystal-is an infinite chain complex,in which four carboxyl groups from glycine molecules bridge theEr<sup>3+</sup> and Y<sup>3+</sup> ions,and the other two carboxyl groups bridge two adjacent Er<sup>3+</sup> or Y<sup>3+</sup> ions.
