A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was bas...A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.展开更多
We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump ...We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump laser in a signal stage of short pulse non-collinear optical parametric chirped pulse amplification. The total gain is more than 106 and the rms energy stability is under 1.35%. The contrast ratio is higher than 10s within a scale of 20ps before the main pulse. Consequently, the improvement factor of the signal contrast is approximately equal to the gain 106 outside the pump window.展开更多
We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating d...We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating design.In a five-pass configuration,the amplifier yields a 42.3 W linearly polarized 1319 nm output at repetition rate of 1 kHz with pulse duration of 75μs and beam quality factors of M^(2)_(x)=1.13 and M^(2)_(y)=2.16 in the orthogonal directions.The fluctuation of the amplifier output power is measured to be±0.6%.Furthermore,a computational model of QCW pulse amplification is employed to examine the amplification process.展开更多
This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd：YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation fiat...This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd：YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation fiat-fiat cavity was adopted as the master oscillator. A solid etalon was inserted in the unidirectional ring resonator to compress the laser linewidth. Under a repetition rate of 500 Hz and pulse width of 160 μs, the master oscillator delivers an average output power of 16.8 W at 1319 nm with linear polarisation, beam quality factor M^2=1.16 and linewidth of 3.2 GHz. A double-pass power amplifier with two amplifier stages was employed for higher power scaling and the output power was amplified to be 25.9 W with M^2 = 1.43.展开更多
We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corre...We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corresponding to a pump extraction efficiency of 16.1%(19.5% for the second stage) and peak power of ~1.5 MW.The beam quality factors at maximum output power are measured to be Mx2= 1.56 and My2= 1.48. We introduce an analytical model to estimate gain and beam quality after amplification. This model focuses on the influence of ratio of seed spot radius to pump spot radius when designing an amplifier. Moreover, our experiments reveal that the re-imaging system in the double-pass configuration can be used to enhance the beam quality.展开更多
A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achiev...A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achieved by double-passing the first amplifier stage and single-passing the second stage with an optical efficiency of 29% while working at a frequency of 1kHz and pulse width of 200 μs.展开更多
Dy^3＋-doped Ge-Ga-Se chalcogenide glasses and GeSe2-Ga2Se3-CsI chalcohalide glasses were prepared. The absorption, emission properties, and local structure of the glasses were investigated. When excited at 808 nm dio...Dy^3＋-doped Ge-Ga-Se chalcogenide glasses and GeSe2-Ga2Se3-CsI chalcohalide glasses were prepared. The absorption, emission properties, and local structure of the glasses were investigated. When excited at 808 nm diode laser, intense 1.32 and 1.55 μm near-infrared luminescence were observed with full width at half maximum （FWHM） of about 90 and 50 nm, respectively. The lifetime of the 1.32 μm emission varied due to changes in the local structure surrounding Dy^3＋ ions. The longest lifetime was over 2.5 ms, and the value was significantly higher than that in other Dy^3＋-doped glasses. Some other spectroscopic parameters were calculated by using Judd-Ofelt theory. Meanwhile, Ge-Ga-Se and GeSe2-Ga2Se3-CsI glasses showed good infrared transmittance. As a result, Dy^3＋-doped Ge-Ga-Se and GeSe2-Ga2Se3-CsI glasses were believed to be useful hosts for 1.3 μm optical fiber amplifier.展开更多
yb^3＋-doped new gallium-lead-germanate glass is presented. Thermal stability, spectroscopic and laser performance parameters of the yb^3＋-doped new gallium-lead-germanate glass are calculated. The results show that ...yb^3＋-doped new gallium-lead-germanate glass is presented. Thermal stability, spectroscopic and laser performance parameters of the yb^3＋-doped new gallium-lead-germanate glass are calculated. The results show that the yb^3＋-doped new gallium-lead-germanate glass has good thermal stability （△T =198℃）, high stimulated emission cross section （0.79pm^2）, and long fluorescence lifetime （1.46ms）. Compared with other Yb^3＋-doped glass hosts, the yb^3＋-doped new gallium-lead-germanate glass has better laser performance parameters and laser properties, indicating that yb^3＋-doped new gallium-lead-germanate glass is a promising laser material for short pulse generation in diode pumped lasers, short pulse generation tunable laser, high-peak power and high-average power lasers.展开更多
The Nd^3＋-doped pared. The absorption and tellurite glasses were preemission spectra of Nd^3 ＋- doped tellurite glasses at room temperature were measured. The Judd-Ofelt parameters （Ω2, Ω4, Ω6） of the glasses w...The Nd^3＋-doped pared. The absorption and tellurite glasses were preemission spectra of Nd^3 ＋- doped tellurite glasses at room temperature were measured. The Judd-Ofelt parameters （Ω2, Ω4, Ω6） of the glasses were calculated from measured absorption spectra. The calculation results of luminescence properties （A, β, τrad, σ） of Nd^3＋ ions in the tellurite were glasses were given. Spectroscopic properties, concentration quenching in these kinds of the glasses were investigated. The results indicate that the tellurite glasses with composition of 70% TeO2, 20% ZnO, （ 10 - x ） % La2O3, x % Nd2O3 （ mol% ） show high emission cross section and low phonon energy. The fluorescent intensity and the emission cross section have a maxi- mum value at x = 0.5, namely, the optimum Nd^3 ＋ ion concentration in the tellurite glass is 0.5% （1.93 × 10^20 ions·cm^-3）. The fluorescence properties of Nd^3＋ measured are basically in accord with the calculated results.展开更多
The glass forming ability (GFA), microstructure and magnetic property in (Nd60Al10Ni10)Cu20-xFex (0≤ x≤ 20) alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), high re...The glass forming ability (GFA), microstructure and magnetic property in (Nd60Al10Ni10)Cu20-xFex (0≤ x≤ 20) alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), high resolution transmission electron mi- croscopy (HRTEM) and magnetic property measurement. It is shown that the GFA of the alloys decreases with Fe content. The sam- ples for bulk cylinders with x≤10 show a distinct endothermic peak in the DSC traces due to a glass transition in the range of 421-438 K. With further increasing Fe, the glass transition is masked by the crystallization. The microstructure of the Nd-based alloy can change progressively from full glassy state into composite state with nanocrystalline particles in the glassy matrix indicating the glass forming ability degrades with increasing Fe. The average size of nanocrystals increases with Fe and the distribution changes from homogenous to heterogeneous. The magnetic property varies from paramagnetic to hard magnetic when the Fe content increases up to about 4at% indicating that the magnetic property is related to the metastable phases.展开更多
The glass-forming ability (GFA) of Nd70-xFe2oAl10Yx and Nd60-xFe30Al10Yx (0< x <15) alloys produced by Cu mold casting was investigated. Except Y=5 at. pct, bulk amorphous Nd70-xFe20Al10Yx alloys up to 2 mm in d...The glass-forming ability (GFA) of Nd70-xFe2oAl10Yx and Nd60-xFe30Al10Yx (0< x <15) alloys produced by Cu mold casting was investigated. Except Y=5 at. pct, bulk amorphous Nd70-xFe20Al10Yx alloys up to 2 mm in diameter were obtained. The GFA for Nd60-xFe30Al10Yx alloys, however, was found to decrease with increase of Y due to the increasing compositional deviation from the original eutectic point of Nd60Fe30Al10 alloy. The Nd60Fe20Al10Y10 and Nd60Fe30Al10 alloy exhibit the largest GFA and can be cast into bulk amorphous cylindrical specimens of 3 mm in diameter. The melting temperature or/and the reduced crystallization temperature is closely related to the GFA of Y-containing alloys. The bulk amorphous cylinder for the Nd55Fe20Al10Y15 alloy shows a distinct glass transition temperature and a wide supercooled liquid region before crystallization. The crystallization temperature, Tg, and the supercooled liquid region, TX, are 776 K and 58 K, respectively. The GFA and thermal stability of the Nd-Fe-AI-Y alloys were discussed.展开更多
A new kind of Nd^3＋-doped high silica glass （SiO2 〉 96% （mass fraction）） was obtained by sintering porous glass impregnated with Nd^3 ＋ ions. The absorption and luminescence properties of high silica glass dope...A new kind of Nd^3＋-doped high silica glass （SiO2 〉 96% （mass fraction）） was obtained by sintering porous glass impregnated with Nd^3 ＋ ions. The absorption and luminescence properties of high silica glass doped with different Nd^3 ＋ concentrations were studied. The intensity parameters Ωt （t = 2, 4, 6）, spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd^3＋ concentration in high silica glass was 0.27% （mole fraction） because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd^3 ＋- doped oxide glasses and commercial silicate glasses, the Nd^3 ＋ -doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.展开更多
对Nd,Y:CaF_2晶体作为激光放大器的增益介质进行了报道.研制了一台采用激光二极管面阵五向水平侧面抽运Ф5 mm×70 mm Nd,Y:CaF_2的激光放大器,对其进行了实验研究.测量了Nd,Y:CaF_2晶体的吸收谱、发射谱、以及放大器的荧光分布.在...对Nd,Y:CaF_2晶体作为激光放大器的增益介质进行了报道.研制了一台采用激光二极管面阵五向水平侧面抽运Ф5 mm×70 mm Nd,Y:CaF_2的激光放大器,对其进行了实验研究.测量了Nd,Y:CaF_2晶体的吸收谱、发射谱、以及放大器的荧光分布.在相同的抽运功率下,测量了Nd,Y:CaF_2与Nd:Glass放大器分别工作在10 Hz和1 Hz重复频率时的小信号增益,在抽运功率为9.63 kW时,Nd,Y:CaF_2放大器的小信号增益达6.12,为Nd:Glass的1.5倍.与Nd:Glass相比,Nd,Y:CaF_2晶体的重复工作频率不仅大大提高,而且增益性能也更强.测量了种子光和经Nd,Y:CaF_2放大器后的光谱,能量放大前后光谱几乎无变化.展开更多
基金supported by the Natural Science Foundation of Zhejiang Provience, China (2006C21082)National Natural Science Foundation of China (60677015)+1 种基金Foundation of Ningbo University (XR0710018)sponsored by KC Wong Magna Fund in NingBo University
文摘A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11604350 and 61405211
文摘We demonstrate a novel picosecond optical parametric preamplification to generate high-stability, high-energy and high-contrast seed pulses. The 5ps seed pulse is amplified from 60pJ to 300μJ with an 8.6ps/ 3mJ pump laser in a signal stage of short pulse non-collinear optical parametric chirped pulse amplification. The total gain is more than 106 and the rms energy stability is under 1.35%. The contrast ratio is higher than 10s within a scale of 20ps before the main pulse. Consequently, the improvement factor of the signal contrast is approximately equal to the gain 106 outside the pump window.
基金Supported by the National Basic Research Program of China under Grant No 2010CB630706the National High-Technology Research and Development Program under Grant No 2011AA030202the National Natural Science Foundation of China under Grant No 50990304.
文摘We report a high power high beam quality quasi-continuous-wave(QCW)diode-end-pumped Nd:YAG slab amplifier at 1319 nm.The strongest 1064 nm parasitic oscillation has been successfully suppressed by reasonable coating design.In a five-pass configuration,the amplifier yields a 42.3 W linearly polarized 1319 nm output at repetition rate of 1 kHz with pulse duration of 75μs and beam quality factors of M^(2)_(x)=1.13 and M^(2)_(y)=2.16 in the orthogonal directions.The fluctuation of the amplifier output power is measured to be±0.6%.Furthermore,a computational model of QCW pulse amplification is employed to examine the amplification process.
基金Project supported by the National High Technology Research and Development Program and the National Natural Science Foundation of China (Grant No. 60508013)
文摘This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd：YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation fiat-fiat cavity was adopted as the master oscillator. A solid etalon was inserted in the unidirectional ring resonator to compress the laser linewidth. Under a repetition rate of 500 Hz and pulse width of 160 μs, the master oscillator delivers an average output power of 16.8 W at 1319 nm with linear polarisation, beam quality factor M^2=1.16 and linewidth of 3.2 GHz. A double-pass power amplifier with two amplifier stages was employed for higher power scaling and the output power was amplified to be 25.9 W with M^2 = 1.43.
基金Supported by the Natural Science Foundation of Guangdong Province under Grant Nos 2017A030310305 and 2018A030310092the Young Teachers Training Program of the Fundamental Research Funds for Sun Yat-sen University under Grant No20174500031610017
文摘We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corresponding to a pump extraction efficiency of 16.1%(19.5% for the second stage) and peak power of ~1.5 MW.The beam quality factors at maximum output power are measured to be Mx2= 1.56 and My2= 1.48. We introduce an analytical model to estimate gain and beam quality after amplification. This model focuses on the influence of ratio of seed spot radius to pump spot radius when designing an amplifier. Moreover, our experiments reveal that the re-imaging system in the double-pass configuration can be used to enhance the beam quality.
文摘A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achieved by double-passing the first amplifier stage and single-passing the second stage with an optical efficiency of 29% while working at a frequency of 1kHz and pulse width of 200 μs.
基金supported by the China’s Manned Space Program (921-21 Project)
文摘Dy^3＋-doped Ge-Ga-Se chalcogenide glasses and GeSe2-Ga2Se3-CsI chalcohalide glasses were prepared. The absorption, emission properties, and local structure of the glasses were investigated. When excited at 808 nm diode laser, intense 1.32 and 1.55 μm near-infrared luminescence were observed with full width at half maximum （FWHM） of about 90 and 50 nm, respectively. The lifetime of the 1.32 μm emission varied due to changes in the local structure surrounding Dy^3＋ ions. The longest lifetime was over 2.5 ms, and the value was significantly higher than that in other Dy^3＋-doped glasses. Some other spectroscopic parameters were calculated by using Judd-Ofelt theory. Meanwhile, Ge-Ga-Se and GeSe2-Ga2Se3-CsI glasses showed good infrared transmittance. As a result, Dy^3＋-doped Ge-Ga-Se and GeSe2-Ga2Se3-CsI glasses were believed to be useful hosts for 1.3 μm optical fiber amplifier.
基金Supported by the National Nature Science Foundation of China under Grant Nos 60508014 and 50502030, and the Key Project of Department of Education of Zhejiang Province under Grant No 20050359.
文摘yb^3＋-doped new gallium-lead-germanate glass is presented. Thermal stability, spectroscopic and laser performance parameters of the yb^3＋-doped new gallium-lead-germanate glass are calculated. The results show that the yb^3＋-doped new gallium-lead-germanate glass has good thermal stability （△T =198℃）, high stimulated emission cross section （0.79pm^2）, and long fluorescence lifetime （1.46ms）. Compared with other Yb^3＋-doped glass hosts, the yb^3＋-doped new gallium-lead-germanate glass has better laser performance parameters and laser properties, indicating that yb^3＋-doped new gallium-lead-germanate glass is a promising laser material for short pulse generation in diode pumped lasers, short pulse generation tunable laser, high-peak power and high-average power lasers.
文摘The Nd^3＋-doped pared. The absorption and tellurite glasses were preemission spectra of Nd^3 ＋- doped tellurite glasses at room temperature were measured. The Judd-Ofelt parameters （Ω2, Ω4, Ω6） of the glasses were calculated from measured absorption spectra. The calculation results of luminescence properties （A, β, τrad, σ） of Nd^3＋ ions in the tellurite were glasses were given. Spectroscopic properties, concentration quenching in these kinds of the glasses were investigated. The results indicate that the tellurite glasses with composition of 70% TeO2, 20% ZnO, （ 10 - x ） % La2O3, x % Nd2O3 （ mol% ） show high emission cross section and low phonon energy. The fluorescent intensity and the emission cross section have a maxi- mum value at x = 0.5, namely, the optimum Nd^3 ＋ ion concentration in the tellurite glass is 0.5% （1.93 × 10^20 ions·cm^-3）. The fluorescence properties of Nd^3＋ measured are basically in accord with the calculated results.
文摘The glass forming ability (GFA), microstructure and magnetic property in (Nd60Al10Ni10)Cu20-xFex (0≤ x≤ 20) alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), high resolution transmission electron mi- croscopy (HRTEM) and magnetic property measurement. It is shown that the GFA of the alloys decreases with Fe content. The sam- ples for bulk cylinders with x≤10 show a distinct endothermic peak in the DSC traces due to a glass transition in the range of 421-438 K. With further increasing Fe, the glass transition is masked by the crystallization. The microstructure of the Nd-based alloy can change progressively from full glassy state into composite state with nanocrystalline particles in the glassy matrix indicating the glass forming ability degrades with increasing Fe. The average size of nanocrystals increases with Fe and the distribution changes from homogenous to heterogeneous. The magnetic property varies from paramagnetic to hard magnetic when the Fe content increases up to about 4at% indicating that the magnetic property is related to the metastable phases.
基金This work was performed with the support of the National Development Project for Basic Scientific Research of China under grant number G2000067201 as well as the fund for the best doctor dissertation .
文摘The glass-forming ability (GFA) of Nd70-xFe2oAl10Yx and Nd60-xFe30Al10Yx (0< x <15) alloys produced by Cu mold casting was investigated. Except Y=5 at. pct, bulk amorphous Nd70-xFe20Al10Yx alloys up to 2 mm in diameter were obtained. The GFA for Nd60-xFe30Al10Yx alloys, however, was found to decrease with increase of Y due to the increasing compositional deviation from the original eutectic point of Nd60Fe30Al10 alloy. The Nd60Fe20Al10Y10 and Nd60Fe30Al10 alloy exhibit the largest GFA and can be cast into bulk amorphous cylindrical specimens of 3 mm in diameter. The melting temperature or/and the reduced crystallization temperature is closely related to the GFA of Y-containing alloys. The bulk amorphous cylinder for the Nd55Fe20Al10Y15 alloy shows a distinct glass transition temperature and a wide supercooled liquid region before crystallization. The crystallization temperature, Tg, and the supercooled liquid region, TX, are 776 K and 58 K, respectively. The GFA and thermal stability of the Nd-Fe-AI-Y alloys were discussed.
基金Project supported bythe National Natural Science Foundation of China (50125258 and 60377040) ,the Shanghai Nano-TechPromote Center (0352nm042)
文摘A new kind of Nd^3＋-doped high silica glass （SiO2 〉 96% （mass fraction）） was obtained by sintering porous glass impregnated with Nd^3 ＋ ions. The absorption and luminescence properties of high silica glass doped with different Nd^3 ＋ concentrations were studied. The intensity parameters Ωt （t = 2, 4, 6）, spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd^3＋ concentration in high silica glass was 0.27% （mole fraction） because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd^3 ＋- doped oxide glasses and commercial silicate glasses, the Nd^3 ＋ -doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.
