We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size s...We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals,such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain(near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.展开更多
A Ti：sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method（HEM）. The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit（FOMs）at d...A Ti：sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method（HEM）. The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit（FOMs）at different positions of the crystal were measured and the FOM value in the central region was found to reach 90.The transmittance laser beam was intact with no obvious distortions and had only a small deformation compared with the incident laser beam. A small-signal amplification experiment was performed on the Ti：sapphire crystal and a gain of more than 6 times was achieved with a pump energy density of 1.98 J∕cm^2. These tests indicate that the 235 mm Ti：sapphire crystal has excellent optical qualities and will further improve the energy output of a 10 PW laser system.展开更多
A novel tiled Ti:sapphire(Ti:S)amplifier was experimentally demonstrated with>1 J amplified chirped pulse output.Two Ti:S crystals having dimensions of 14 mm×14 mm×25 mm were tiled as the gain medium in a...A novel tiled Ti:sapphire(Ti:S)amplifier was experimentally demonstrated with>1 J amplified chirped pulse output.Two Ti:S crystals having dimensions of 14 mm×14 mm×25 mm were tiled as the gain medium in a four-pass amplifier.Maximum output energy of 1.18 J was obtained with 2.75 J pump energy.The energy conversion efficiency of the tiled Ti:S amplifier was comparable with a single Ti:S amplifier.The laser pulse having the maximum peak power of 28 TW was obtained after the compressor.Moreover,the influence of the beam gap on the far field was discussed.This novel tiled Ti:S amplifier technique can provide a potential way for 100 PW or EW lasers in the future.展开更多
The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effec...The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effect is equivalent to the process of degenerate four-wave frequency-mixing. Based on this theoretical underpinning, the presence or absence of a multipeak spectrum provides a practical measure of whether the intracavity group-velocity-dispersion is ideally compensated for or not.展开更多
钛蓝宝石晶体作为一种重要的激光介质,具有宽带的吸收光谱及宽带可调谐的发射光谱等特性,使其在集成光学中有广泛的应用前景。这里利用重复频率为1 k Hz,中心波长为800 nm,脉冲宽度为120 fs的飞秒脉冲激光在钛蓝宝石晶体中横向刻写双线...钛蓝宝石晶体作为一种重要的激光介质,具有宽带的吸收光谱及宽带可调谐的发射光谱等特性,使其在集成光学中有广泛的应用前景。这里利用重复频率为1 k Hz,中心波长为800 nm,脉冲宽度为120 fs的飞秒脉冲激光在钛蓝宝石晶体中横向刻写双线型波导,系统地研究了激光写入晶体深度、刻写速度以及波导双线间距对波导导光情况的影响,在写入激光脉冲能量为2μJ,写入深度为175μm,刻写速度为90μm/s,波导双线间距为26μm的条件下,得到一组导光模式较优的双线波导并发现其具有偏振导光现象。利用波导的近场模式强度分布重构了其折射率分布图,得到最大的折射率增加量为1.9×10-4。用散射法测试了光波导的传输损耗为1.82 d B/cm。展开更多
基金partially supported by the National Basic Research Program of China (Grant No. 2011CB808101)the National Natural Science Foundation of China (NSFC) (Grant Nos. 61221064, 61078037, 11127901, 11134010)the International S&T Cooperation Program of China (Grant No. 2011DFA11300)
文摘We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals,such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain(near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.
基金supported by the National Natural Science Foundation of China(Nos.61775223 and 51502321)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB1603)the Shanghai Scientific Research Project(Nos.16JC1420600 and 16DZ0503900)
文摘A Ti：sapphire crystal with a diameter of 235 mm and thickness of 72 mm was grown by the heat exchange method（HEM）. The absorption intensity of the crystal at 532 nm averaged at 91%. The figures of merit（FOMs）at different positions of the crystal were measured and the FOM value in the central region was found to reach 90.The transmittance laser beam was intact with no obvious distortions and had only a small deformation compared with the incident laser beam. A small-signal amplification experiment was performed on the Ti：sapphire crystal and a gain of more than 6 times was achieved with a pump energy density of 1.98 J∕cm^2. These tests indicate that the 235 mm Ti：sapphire crystal has excellent optical qualities and will further improve the energy output of a 10 PW laser system.
基金the National Key R&D Program of China(No.2017YFE0123700)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB1603)+2 种基金the National Natural Science Foundation of China(No.61925507)the Program of Shanghai Academic/Technology Research Leader(No.18XD1404200)the Shanghai Municipal Science and Technology Major Project(No.2017SHZDZX02)。
文摘A novel tiled Ti:sapphire(Ti:S)amplifier was experimentally demonstrated with>1 J amplified chirped pulse output.Two Ti:S crystals having dimensions of 14 mm×14 mm×25 mm were tiled as the gain medium in a four-pass amplifier.Maximum output energy of 1.18 J was obtained with 2.75 J pump energy.The energy conversion efficiency of the tiled Ti:S amplifier was comparable with a single Ti:S amplifier.The laser pulse having the maximum peak power of 28 TW was obtained after the compressor.Moreover,the influence of the beam gap on the far field was discussed.This novel tiled Ti:S amplifier technique can provide a potential way for 100 PW or EW lasers in the future.
文摘The multi-peak spectrum of Ti: sapphire pulses observed experimentally under ultra-broad bandwidth conditions ( 【 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effect is equivalent to the process of degenerate four-wave frequency-mixing. Based on this theoretical underpinning, the presence or absence of a multipeak spectrum provides a practical measure of whether the intracavity group-velocity-dispersion is ideally compensated for or not.
文摘钛蓝宝石晶体作为一种重要的激光介质,具有宽带的吸收光谱及宽带可调谐的发射光谱等特性,使其在集成光学中有广泛的应用前景。这里利用重复频率为1 k Hz,中心波长为800 nm,脉冲宽度为120 fs的飞秒脉冲激光在钛蓝宝石晶体中横向刻写双线型波导,系统地研究了激光写入晶体深度、刻写速度以及波导双线间距对波导导光情况的影响,在写入激光脉冲能量为2μJ,写入深度为175μm,刻写速度为90μm/s,波导双线间距为26μm的条件下,得到一组导光模式较优的双线波导并发现其具有偏振导光现象。利用波导的近场模式强度分布重构了其折射率分布图,得到最大的折射率增加量为1.9×10-4。用散射法测试了光波导的传输损耗为1.82 d B/cm。
