1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室，上海 201800
2 中国科学院大学材料科学与光电工程中心，北京 100049
3 张江实验室，上海 201210
利用百太瓦级激光系统在氖气（Ne）中得到基于高次谐波产生的极紫外脉冲。通过松聚焦结构在13 nm波段产生单级次单脉冲能量为13.5 nJ（13.1 nm波长）和11.1 nJ（13.5 nm波长）的高次谐波辐射，转换效率为和，谐波发散角的半高全宽为0.32 mrad和0.33 mrad。对含时薛定谔方程进行数值求解，得到单原子偶极发射谱，结合麦克斯韦方程组模拟传播效应，同时考虑气体对谐波的吸收效应，理论模拟得到的信号强度随气压和光强的变化趋势与实验结果基本符合。实现相位匹配的谐波光束质量很好，纵向空间分布为高斯型。结合相位匹配条件和空间分布的分析得到了目前激光参数下的最优相位匹配条件。这种基于高次谐波机制的高能量相干极紫外光源在作为自由电子激光的种子光源以及超快非线性实验和半导体工业检测等方面具有广阔的应用前景。
极紫外 高次谐波 相位匹配 空间分布
Author Affiliations
Abstract
1 School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
2 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
High-order harmonic generation originated from zigzag graphene nanoribbons (ZGNRs) induced by intense laser pulses is investigated theoretically. During the interaction between the intense mid-infrared laser and the ZGNR, we find that localized edge states mainly contribute to the generation of the low-order harmonics, while cutoff harmonics result from the other confined states. Our result shows that the edge-state effect of ZGNR with narrow width can enhance the conversion efficiency of low-order harmonics, rather than the higher-order harmonics extended to the cutoff region.
graphene nanoribbons high-order harmonic generation edge state Chinese Optics Letters
2020, 18(10): 103201
1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室和超强激光科学卓越中心, 上海 201800
2 中国科学院大学, 北京 100049
阿秒瞬态吸收(Attosecond Transient Absorption, ATA)谱是一种非常有用的研究原子分子中亚飞秒时间尺度超快动力学的技术。通过数值求解含时薛定谔方程,模拟了氢分子离子( H2+)在近红外(NIR)和深紫外(XUV)强复合激光场中的演化,对比了 H2+在核动和不动两种情形下ATA谱的异同。研究结果显示,当核不动时,所得的ATA谱与原子下的结构类似;当核动时,ATA谱呈现出丰富的周期调制的吸收线结构,而且其调制周期恰好等于NIR光周期的一半。通过分析 H2+的电离解离特性,证实了该半周期调制是源于 H2+基态和激发态的不同量子跃迁路径间的干涉。对比两种情形下的ATA谱,可以看出核运动对分子ATA谱的显著影响。
超快光学 瞬态吸收谱 阿秒脉冲 含时薛定谔方程 半周期调制
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
We theoretically investigate the attosecond pulse generation in an orthogonal multicycle midinfrared two-color laser field. It is demonstrated that multiple continuum-like humps, which consist of about twenty orders of harmonics and an intensity of about one order higher than the adjacent normal harmonics, are generated when longer wavelength driving fields are used. By filtering these humps, intense isolated attosecond pulses (IAPs) are directly generated without any phase compensation. Our proposal provides a simple technique to generate intense IAPs with various central photon energies covering the multi-keV spectral regime by using multicycle midinfrared driving pulses with high pump energy in the experiment.
190.2620 Harmonic generation and mixing 020.2649 Strong field laser physics 320.2250 Femtosecond phenomena Chinese Optics Letters
2017, 15(7): 071901
1 上海大学理学院, 上海 200444
2 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
采用长焦距透镜与连续介质气体靶是目前高亮度高次谐波产生实验中谐波产率较高的方案, 在长焦距透镜方案中进一步探索使用准相位匹配技术, 有望在连续介质靶的基础上进一步提高高次谐波信号的强度。根据准相位匹配技术, 设计了一种多喷嘴阵列气体靶, 通过模拟计算的方法, 对比传统连续介质气体靶与多喷嘴气体靶这两种方案, 从理论上证实多喷嘴气体靶可以实现谐波信号强度的进一步提升。
超快光学 高次谐波 准相位匹配 多喷嘴阵列 中国激光
2017, 44(10): 1001002
Author Affiliations
Abstract
1 School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
2 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Department of Physics, Shaoxing University, Shaoxing 312000, China
We experimentally and theoretically demonstrate that the property (odd or even) of generated harmonics can be selected by manipulating the macroscopic phase-matching conditions based on a three-color laser field. Only odd or even harmonics can be made dominant by changing the focal position and adjusting the gas pressure. These results indicate that the odd-even property of the generated harmonics can be controlled by using the multi-color laser field with macroscopic phase-matching.
020.1335 Atom optics 020.2649 Strong field laser physics 190.2620 Harmonic generation and mixing Chinese Optics Letters
2015, 13(5): 050202
中国科学院 上海光学精密机械研究所 强场激光物理国家重点实验室, 上海201800
激光与光电子学进展
2010, 47(3): 03SC01
Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
A new physical explanation of the fringes in the high-order harmonic spectra generated by ellipticity-modulated infrared pulses is proposed, which is different from those in previous works. In this work we find that the fringes are due to the spectral interference effect induced by the two outgoing pulses with a delay, which are generated by the wave plates for ellipticity control. The visibility of interference fringes observed experimentally increases with the increase of the asymmetry of the two pulses, with the decrease of the delay and with the increase of peak intensity of the driving laser pulse. The experimental results are in good agreement with the calculated ones.
120.2650 Fringe analysis 190.4160 Multiharmonic generation Chinese Optics Letters
2007, 5(s1): 118
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
2 Graduate School of the Chinese Academy of Sciences, Beijing 100039
3 Department of Physics, Zaozhuang University, Zaozhuang 277160
Phase locking for two ytterbium-doped large-core fiber lasers has been demonstrated by using a self-imaging confocal resonator with a spatial filter. Steady high-contrast interference stripes are observed. The visibilities of coherent and incoherent stripes are 59% and 6%, respectively. The measured width of the central strip is in good agreement with the calculated result. For in-phase mode, the output power of the phase-locked fiber laser array is up to 113 W and corresponding slope efficiency is 38.5%.
光纤激光器 位相锁定 自成像 060.2320 Fiber optics amplifiers and oscillators 140.3290 Laser arrays 030.1670 Coherent optical effects 070.6110 Spatial filtering Chinese Optics Letters
2007, 5(7): 412
1 华东师范大学物理系,光谱学与波谱学教育部重点实验室, 上海 200062
2 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
脉冲宽度40 fs,功率1.1 W的载波包络相位(CEP)稳定的飞秒激光脉冲在充氩气的空芯光纤内由于自相位调制频谱展宽，通过啁啾镜和斜劈补偿色散,最终可获得脉冲宽度为6 fs的载波包络相位稳定的强激光脉冲。将之应用到高次谐波实验中得到了脉冲宽度为500 as的单个阿秒脉冲。
超快光学 6 fs脉冲 频谱展宽 载波包络相位稳定 高次谐波
