基于电光开关的高功率准分子激光MOPA系统ASE抑制
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摘要
高功率准分子激光系统中的放大自发辐射(ASE)会引起主脉冲信号对比度下降,从而导致放大过程中激光脉冲信号对比度下降以及波形展宽和畸变,影响精密物理实验的开展。基于电光开关产生短脉冲的原理,对紫外波段电光开关进行了研究,建立了一种抑制准分子激光放大链ASE的方法。在对主振荡功率放大(MOPA)系统第一级预放大器的削波实验中,单电光开关和双电光开关消光比分别达到了103和104量级,削波后的激光脉冲信号对比度由原来的几十倍分别提高到105和106量级。在单路MOPA系统放大实验中,采用级联双电光开关进行了系统的ASE控制,并最终在靶面获得了良好的窄脉宽放大激光脉冲,为高功率准分子激光系统中波形放大问题提供了一个有效的解决方案。
In high power excimer laser system,the signal contrast ratio is decreased severely by the amplified spontaneous emission(ASE),which decreases the laser pulse signal contrast severely,leads to waveform broadening and distortion,and impacts on the accurate physical experiment.In this paper,based on the principle of the short pulse generation by electro-optical switch,study on ultraviolet electro-optical switch is made,and a method for ASE suppression of the laser amplifier chain is established.In the waveform clipping experiment of the first pre-amplifier in master oscillator power amplifier(MOPA) system,the extinction ratios of the single and cascaded dual electro-optical switches reach 103 and 104 level,and the laser pulse signal contrast ratios are promoted to 105 and 106 level after clipping,respectively.In the experiment of single channel MOPA system,the cascaded dual electro-optical switch is adopted to control the ASE,and an amplified narrow pulse is obtained on the target surface,providing an effective solution to the problem of waveform amplification in the high power excimer laser system.
In high power excimer laser system,the signal contrast ratio is decreased severely by the amplified spontaneous emission(ASE),which decreases the laser pulse signal contrast severely,leads to waveform broadening and distortion,and impacts on the accurate physical experiment.In this paper,based on the principle of the short pulse generation by electro-optical switch,study on ultraviolet electro-optical switch is made,and a method for ASE suppression of the laser amplifier chain is established.In the waveform clipping experiment of the first pre-amplifier in master oscillator power amplifier(MOPA) system,the extinction ratios of the single and cascaded dual electro-optical switches reach 103 and 104 level,and the laser pulse signal contrast ratios are promoted to 105 and 106 level after clipping,respectively.In the experiment of single channel MOPA system,the cascaded dual electro-optical switch is adopted to control the ASE,and an amplified narrow pulse is obtained on the target surface,providing an effective solution to the problem of waveform amplification in the high power excimer laser system.
引文
1T.Lehecka,R.H.Lehmberg,A.V.Deniz et al..Productionof high energy,uniform focal profiles with the Nike laser[J].Opt.Commun.,1995,117(5-6):485～491
2A.V.Deniz,S.P.Obenschain.A KrF oscillator system withuniform profiles[J].Opt.Commun.,1994,106(1-3):113～118
3M.S.Pronko,A.V.Deniz,V.Yun et al..Nanosecondswitching,high-contrast Pockels cell with plasma electrodes[C].Conference on Lasers and Electro-Optics,1996.435～436
4S.P.Obenschain.The Nike KrF laser facility performance andinitial target experiments[J].Physics of Plasmas,1996,3(5):2098～2107
5Guan Haibing,Ye Yunxia,Lu Jinzhong et al..Effect ofamplified spontaneous emission on residual stress of 7050aluminum alloy by laser shock processing[J].Chinese J.Lasers,2010,37(8):2121～2125管海兵,叶云霞,鲁金忠等.放大自发辐射对激光强化7050铝合金残余应力的影响[J].中国激光,2010,37(8):2121～2125
6Zhang Xiongjun,Wu Dengsheng,Zhang Jun et al..Research onrepetition rate plasma Pockels cell with 20mm aperture[J].ActaOptica Sinica,2010,30(6):1772～1775张雄军,吴登生,张君等.20mm孔径重复频率等离子体电光开关研究[J].光学学报,2010,30(6):1772～1775
7Xiang Shiqing,Dong Jingxing,Mang Yanping et al..Generationof 2～10ns XeCl laser pulses by direct wave clipping with anelectro-optical Q-switching[J].Chinese J.Lasers,1995,22(9):675～680向世清,董景星,莽燕萍等.电光开关削波产生2～10ns准分子激光输出脉冲[J].中国激光,1995,22(9):675～680
8Meng Shaoxian,Gu Zhongming,Mang Yanping et al..Choppedwaveshape of electro-optic gates and shorten pulses in laseramplification process[J].Chinese J.Lasers,1998,25(10):930～934孟绍贤,谷忠民,莽燕萍等.电光开关削波和激光放大过程中的脉冲变窄[J].中国激光,1998,25(10):930～934
9Zhang Xiongjun,Wu Dengsheng,Zheng Kuixing et al..Electro-optical switch with 280 mm×280 mm aperture drived by one-pulse process[J].Acta Optica Sinica,2006,26(2):254～258张雄军,吴登生,郑奎兴等.280mm×280mm口径单脉冲过程电光开关[J].光学学报,2006,26(2):254～258
10Lan Xinju.Laser Technology[M].Wuhan:HuazhongUniversity of Science and Technology Press,1995.6～21蓝信钜.激光技术[M].武汉:华中科技大学出版社,1995.6～21
11He Zhongwu.Research on High Extinction Rate Electro-OpticalSwitch Technology[D].Mianyang:China Academy ofEngineering Physics,2002何忠武.高消光比电光开关技术研究[D].绵阳:中国工程物理研究院,2002
12Li Shichen,Ni Wenjun,Yang Tianxin et al..Studies on crystalKTP(KTiPO4)electro-optic switch[J].J.Optoelectronics.Laser,1999,10(2):95～98李世忱,倪文俊,杨天新等.KTP(KTiPO4)晶体电光开关研究[J].光电子.激光,1999,10(2):95～98
13Lu Xiuquan,Chen Shaohe.KTP electro-optic switch[J].ChineseJ.Lasers,1999,26(4):321～324卢秀权,陈绍和.KTP电光开关[J].中国激光,1999,26(4):321～324
14Ren Gang,Zheng Jiangang,Cai Bangwei et al..Influence of off-axis-light on depolarization loss of electro-optical crystal[J].High Power Laser and Particle Beams,2004,16(1):59～62任钢,郑建刚,蔡邦维等.离轴光线对电光晶体退偏的影响[J].强激光与粒子束,2004,16(1):59～62
15Hu Yun,Zhao Xueqing,Xue Quanxi et al..BBO electro-opticalswitch for UV laser[J].Laser&Optoelectronics Progress,2010,47(11):111401胡云,赵学庆,薛全喜等.用于紫外激光的BBO电光削波开关[J].激光与光电子学进展,2010,47(11):111401
2A.V.Deniz,S.P.Obenschain.A KrF oscillator system withuniform profiles[J].Opt.Commun.,1994,106(1-3):113～118
3M.S.Pronko,A.V.Deniz,V.Yun et al..Nanosecondswitching,high-contrast Pockels cell with plasma electrodes[C].Conference on Lasers and Electro-Optics,1996.435～436
4S.P.Obenschain.The Nike KrF laser facility performance andinitial target experiments[J].Physics of Plasmas,1996,3(5):2098～2107
5Guan Haibing,Ye Yunxia,Lu Jinzhong et al..Effect ofamplified spontaneous emission on residual stress of 7050aluminum alloy by laser shock processing[J].Chinese J.Lasers,2010,37(8):2121～2125管海兵,叶云霞,鲁金忠等.放大自发辐射对激光强化7050铝合金残余应力的影响[J].中国激光,2010,37(8):2121～2125
6Zhang Xiongjun,Wu Dengsheng,Zhang Jun et al..Research onrepetition rate plasma Pockels cell with 20mm aperture[J].ActaOptica Sinica,2010,30(6):1772～1775张雄军,吴登生,张君等.20mm孔径重复频率等离子体电光开关研究[J].光学学报,2010,30(6):1772～1775
7Xiang Shiqing,Dong Jingxing,Mang Yanping et al..Generationof 2～10ns XeCl laser pulses by direct wave clipping with anelectro-optical Q-switching[J].Chinese J.Lasers,1995,22(9):675～680向世清,董景星,莽燕萍等.电光开关削波产生2～10ns准分子激光输出脉冲[J].中国激光,1995,22(9):675～680
8Meng Shaoxian,Gu Zhongming,Mang Yanping et al..Choppedwaveshape of electro-optic gates and shorten pulses in laseramplification process[J].Chinese J.Lasers,1998,25(10):930～934孟绍贤,谷忠民,莽燕萍等.电光开关削波和激光放大过程中的脉冲变窄[J].中国激光,1998,25(10):930～934
9Zhang Xiongjun,Wu Dengsheng,Zheng Kuixing et al..Electro-optical switch with 280 mm×280 mm aperture drived by one-pulse process[J].Acta Optica Sinica,2006,26(2):254～258张雄军,吴登生,郑奎兴等.280mm×280mm口径单脉冲过程电光开关[J].光学学报,2006,26(2):254～258
10Lan Xinju.Laser Technology[M].Wuhan:HuazhongUniversity of Science and Technology Press,1995.6～21蓝信钜.激光技术[M].武汉:华中科技大学出版社,1995.6～21
11He Zhongwu.Research on High Extinction Rate Electro-OpticalSwitch Technology[D].Mianyang:China Academy ofEngineering Physics,2002何忠武.高消光比电光开关技术研究[D].绵阳:中国工程物理研究院,2002
12Li Shichen,Ni Wenjun,Yang Tianxin et al..Studies on crystalKTP(KTiPO4)electro-optic switch[J].J.Optoelectronics.Laser,1999,10(2):95～98李世忱,倪文俊,杨天新等.KTP(KTiPO4)晶体电光开关研究[J].光电子.激光,1999,10(2):95～98
13Lu Xiuquan,Chen Shaohe.KTP electro-optic switch[J].ChineseJ.Lasers,1999,26(4):321～324卢秀权,陈绍和.KTP电光开关[J].中国激光,1999,26(4):321～324
14Ren Gang,Zheng Jiangang,Cai Bangwei et al..Influence of off-axis-light on depolarization loss of electro-optical crystal[J].High Power Laser and Particle Beams,2004,16(1):59～62任钢,郑建刚,蔡邦维等.离轴光线对电光晶体退偏的影响[J].强激光与粒子束,2004,16(1):59～62
15Hu Yun,Zhao Xueqing,Xue Quanxi et al..BBO electro-opticalswitch for UV laser[J].Laser&Optoelectronics Progress,2010,47(11):111401胡云,赵学庆,薛全喜等.用于紫外激光的BBO电光削波开关[J].激光与光电子学进展,2010,47(11):111401