Author Affiliations
Abstract
1 Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
2 XXL—The Extreme Optoelectromechanics Laboratory, School of Physics and Electronics Science, East China Normal University, Shanghai 200241, China
3 Joint Research Center of Light Manipulation Science and Photonic Integrated Chip of East China Normal University and Shandong Normal University, East China Normal University, Shanghai 200241, China
4 Collaborative Innovation Center of Light Manipulation and Applications, Shandong Normal University, Jinan 250358, China
To improve the processing efficiency and extend the tuning range of 3D isotropic fabrication, we apply the simultaneous spatiotemporal focusing (SSTF) technique to a high-repetition-rate femtosecond (fs) fiber laser system. In the SSTF scheme, we propose a pulse compensation scheme for the fiber laser with a narrow spectral bandwidth by building an extra-cavity pulse stretcher. We further demonstrate truly 3D isotropic microfabrication in photosensitive glass with a tunable resolution ranging from 8 μm to 22 μm using the SSTF of fs laser pulses. Moreover, we systematically investigate the influences of pulse energy, writing speed, processing depth, and spherical aberration on the fabrication resolution. As a proof-of-concept demonstration, the SSTF scheme was further employed for the fs laser-assisted etching of complicated glass microfluidic structures with 3D uniform sizes. The developed technique can be extended to many applications such as advanced photonics, 3D biomimetic printing, micro-electromechanical systems, and lab-on-a-chips.
simultaneous spatiotemporal focusing technique pulse compensation pulse stretcher 3D isotropic fabrication chemical etching Opto-Electronic Advances
2023, 6(10): 230066
1 西安电子科技大学物理与光电工程学院, 陕西 西安 710126
2 中国科学院物理研究所, 北京凝聚态物理国家实验室, 北京 100190
3 松山湖材料实验室, 广东 东莞 523808
4 中国科学院大学物理学院, 北京 100049
在啁啾脉冲放大 (CPA) 系统中, 时域展宽器与压缩器的匹配是获得高对比度飞秒脉冲的关键。相比较常规的 Martinez 和 ffner 结构的展宽器, 基于同心结构的展宽器由于物与像完全重合, 可以消除像差带来的高阶色散的影响, 进而采用光栅对压缩器以获得更好的压缩效果。透射光栅对和凹面反射镜组合实现的同心展宽器具有结构紧凑的优点, 将该展宽器替代原有的 Martinez 型展宽器, 在重复频率为 1 kHz、泵浦功率为 11.4 W 的泵浦条件下, 展宽后的啁啾脉冲经环形腔钛宝石再生放大器进行能量放大, 再由光栅对进行压缩, 可获得脉冲宽度为 47.5 fs 的压缩结果, 接近于光谱带宽 22.1 nm 的傅里叶变换极限。该结果表明基于透射光栅的同心展宽器可以获得较好的飞秒脉冲压缩效果。
激光技术 飞秒激光 啁啾脉冲放大 脉冲展宽器 再生放大器 laser techniques femtosecond laser chirped-pulse amplification pulse stretcher regenerative amplifier
清华大学 工程物理系 核技术及应用研究所, 北京 100084
采用特殊结构的块材料作为脉冲展宽器的紧凑型掺钛蓝宝石再生放大器设计, 相对传统设计展宽器结构更加简洁可靠, 利用棱栅对结构进行脉冲压缩, 在25 W, 527 nm, 1 kHz的激光泵浦条件下, 输出单脉冲能量为3.5 mJ, 重复频率1 kHz, 脉冲宽度为30 fs的超快激光脉冲.稳定性测试发现, 8 h功率抖动性小于0.7%.
再生放大 脉冲展宽 色散 飞秒脉冲 棱栅对 Regenerative amplifier Pulse stretcher Dispersion Femtosecond laser pulse Grism
Author Affiliations
Abstract
国家高功率激光物理实验室,中国科学院上海光学精密机械研究所,上海201800
The impact of the stretcher on the contrast ratio of the out pulse is analyzed making use of the ray -tracing method , which is based on the contrast ratio model of chirped pulse.When the beam size in the stretcher is increased from 2 mm to 40 mm ,the contrast of the output pulse approximately increase two magnitude. When the input pulse is Sech2 ,the contrast of the output pulse is better than what the input pulse is Gassian or Rectangular.
啁啾脉冲放大 对比度 脉冲展宽器 脉冲对比度 Chirped pulse amplification Contrast Pulse stretcher Pulse contrast ratio Collection Of theses on high power laser and plasma physics
2008, 6(1): 69
Author Affiliations
Abstract
中国科学院上海光学精密机械研究所国家高功率激光物理实验室, 上海 201800
In the design of the Offner stretcher, it is very important to investigate the mirror curvature radius errors, which has a direct impact on the quality of the output pulse. So it is necessary to analyse the effect on the output pulse contrast due to the mirror curvature radius manufacture errors in the ffner stretcher. A ray-tracing model for ffner stretcher with these errors is established. Based on the model, effects on output pulse contrast through the stretcher is analyzed.When the mirror curvature radius error is between 0.2%～0.5%, it can fully meet the requirements for the SHENGUANG Ⅱ petawatt laser facility. Also, when there is error for the mirror curvature radius, keeping the distance between concave mirror and convex mirror half of curvature radius of the concave mirror is better than keeping the two curve mirrors in the same center.
非线性光学 啁啾脉冲放大 展宽器 光线追迹 脉冲对比度 加工误差 nonlinear optics chirped pulse amplification pulse stretcher ray tracing pulse contrast manufacture error Collection Of theses on high power laser and plasma physics
2008, 6(1): 63
Author Affiliations
Abstract
中国科学院上海光学精密机械研究所国家高功率激光物理实验室, 上海 201800
In a stretcher,it is important of spectral clipping. It has a direct impact on the quality of the output pulse. Base on the ray-tracing,an analytical spectral clipping model is present in the ffner stretcher . When the stretcher parameters is determined, the location of the grating placed has a very important influence on the pulse spectral clipping. When the grating placed on the symmetric center about optical axis, the spectral distribution through stretcher will be asymmetric about center wavelength of the laser, that is to say,the spectral clipping will be asymmetric spectral clipping.Therefore,the output pulse contrast will be droped approximately one magnitude in the SGII ninth beam petawatt upgrade laser facility. In order to keeping the spectral symmetry distribution about center wavelength of the laser through the stretcher, the grating must be placed on the asymmetrical position about optical axis.
超快光学 啁啾脉冲放大 脉冲对比度 展宽器 光谱剪切 ultrafast optics chirped pulse amplification pulse contrast ratio pulse stretcher spectral clipping Collection Of theses on high power laser and plasma physics
2008, 6(1): 58
中国科学院上海光学精密机械研究所国家高功率激光物理实验室, 上海 201800
Offner展宽器的设计研究中,对曲面镜曲率半径的误差研究非常重要,它直接影响输出脉冲的质量。因此有必要分析ffner展宽器中曲面镜曲率半径的误差对输出脉冲对比度的影响。参考ffner展宽器的光线追迹模型,建立了ffner展宽器中曲面镜曲率半径存在误差时的光线追迹模型; 根据建立的模型,详细分析了曲面镜曲率半径的误差对输出脉冲质量的影响; 发现在目前曲面镜曲率半径的加工误差在0.2%～0.5%的情况下,完全可以满足神光II拍瓦激光装置中对展宽器的要求; 同时发现如果曲面镜曲率半径存在误差时,应该尽量使两曲面镜之间的距离保持为凹面反射镜曲率半径的一半,而不是使两曲面镜保持同心。
非线性光学 啁啾脉冲放大 展宽器 光线追迹 脉冲对比度 加工误差
中国科学院上海光学精密机械研究所国家高功率激光物理实验室, 上海 201800
在展宽器中,光谱的剪切情况非常重要,它直接影响输出脉冲的质量。以ffner展宽器为例,参照以往建立的光线追迹模型,建立了分析展宽器中光谱剪切的模型。发现当展宽器的参数确定好后,光栅放置的位置对激光脉冲光谱剪切有非常重要的影响。当光栅相对于光轴中心对称放置时,展宽器容许通过的光谱相对于激光中心波长将是非对称分布的,即此时在展宽器中发生的光谱剪切为非对称光谱剪切,在神光II第9路拍瓦激光装置中,这种非对称光谱剪切将使输出脉冲对比度下降一个数量级。为了使展宽器中通过的光谱相对于激光中心波长对称分布,需要将光栅相对于光轴非中心对称放置。
超快光学 啁啾脉冲放大 脉冲对比度 展宽器 光谱剪切
以群速度色散展宽脉冲理论和基尔霍夫-菲涅耳积分为基础,合理地设计了一种紧凑有效的飞秒脉冲展宽器,不仅获得了较大的脉冲展宽比,而且光束通过展宽器后其空间特性也得到恢复。
群速度色散 基尔霍夫-菲涅耳积分 飞秒脉冲展宽器
