基于孔耦合带状线的激光脉冲整形系统
文献类型：学位论文
| 作者 | 高云凯 |
| 学位类别 | 硕士 |
| 答辩日期 | 2005 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 李学春 |
| 关键词 | 激光技术 高功率激光 脉冲整形 电光调制器 孔耦合带状线 |
| 其他题名 | A Laser Pulse-Shaping System Based on Aperture-Coupled Striplines |
| 中文摘要 | 前端作为高功率固体激光器的一个重要分系统，将为后级系统提供一个具有一定能量、高光束质量以及高信噪比的种子激光脉冲。由于后级系统中的主放部分的增益饱和效应会使激光脉冲产生一定时域畸变，所以需要前端系统对种子激光脉冲进行时域整形以预补偿这种时域畸变。本文研究了一种新型激光脉冲整形系统，该系统能够产生具有15Ops前沿、1-5ns脉冲宽度可调、高对比度、光滑过渡以及灵活整形的激光脉冲。第一章概述与比较了目前已有的几种激光脉冲时域整形技术。它们分别为：时空变换激光脉冲整形技术、高压变阻抗传输线激光脉冲整形技术、基于电脉冲堆积的激光脉冲整形技术、光纤堆积脉冲整形技术。第二章介绍了基于孔藕合带状线的激光脉冲整形系统的工作原理。该系统使用了一个由孔祸合带状线电脉冲整形器驱动的电光调制器。一个电脉冲整形器由两条通过其公共接地板上的藕合孔径发生祸合作用的带状传输线所组成的四层四端口装置。更换具有不同藕合孔径的公共接地板，该电脉冲整形发生器可以输出具有150ps时间结构的整形电脉冲。将整形的电脉冲输入到电光调制器上，就可以得到整形激光脉冲。第章阐述了基于孔耦合带状线的激光脉冲整形系统的研制下作。测定了传输线有效阻抗与孔径宽度之间的对应关系。利用该激光脉冲整形系统，获得了各种形状的激光脉冲的输出：第四章计算了高功率固体激光器后级主放系统的增益饱和效应。以终端输出方波为例，推算出所需要的前端系统输出激光脉冲的时间形状。计算的结果为前端系统激光脉冲的输出提供了设计依据。第五章在本文所提的激光脉冲整形技术的基础上，首次创造性地提出一种新的长短激光脉冲同步方案。在该方案中，100ns的单纵模激光预脉冲经分束后分别输入到两个波导调制器中，与此同时分别输入两个具有高同步精度的电脉冲到调制器中，通过这种方式可以实现具有高同步精度的100ps激光脉冲和ns激光脉冲的输出。初步实验结果表明该方案是可实现高精度长短脉冲同步输出的。该技术方案可以为长短脉冲同步提供了一条新的技术思路。第五章本文的主要结论。 |
| 英文摘要 | As a important subsystem of the ICF high power solid-state laser driver, the front-end will provide a seed laser pulse with proper energy, high quality and high SNR(signal to noise ratio). The temporal profile of the seed pulse will be distorted by the gain saturation in the subsequent main amplifier, so the front-end need be capable of producing arbitrarily laser pulse in order to compensate the gain distortion. In this paper, a new laser pulse-shaping system using an electro-optic modulator driven by an aperture-coupled-striplines(ACSL) electrical-waveform generator has been discussed. By the new technique, the front-end will emit arbitrarily shaped laser pulses with about 150ps structure, l-5ns pulse envelope, high contrast waveform and slippery transition waveform. In the first chapter, some laser pulse-shaping techniques have been discussed. These techniques include the temporal-spatial transform pulse-shaping system, the arbitrary pulse-shaping system in nonuniform transmission lines, the waveguide laser pulse-shaping system on NIF( National Ignition Facility), the flexible pulse shaping of partially coherent light on Gekko XII. In the second chapter, the laser pulse-shaping system using an electro-optic modulator driven by an aperture-coupled-striplines(ACSL) electrical-waveform generator has been discussed. The ACSL electrical-waveform generator consists of two striplines coupled through an aperture in their common ground plane. Replacing the aperture layer ,the electrical-waveform can produce arbitrary electrical pulse with 100-ps structure. Giving the arbitrary electrical to the electro-optic modulator, arbitrary laser pulse can be gotten. In the third chapter, the fabrication of the ACSL pulse-shaping system has been discussed. The effective impedance versus aperture width has been measured practically. By using the pulse-shaping system, shaped optic waveforms has been obtained. In the fourth chapter, the gain saturation in the main amplifier has been calculated in order to get the temporal profile of the laser pulse emitted from the front-end system. In the fifth chapter, a new scheme of time- synchronization between the 150ps laser pulse and the l-5ns laser pulse has been discussed. A long pulse of single longitudinal laser is input into two waveguide modulators respectively after beam splitting, meanwhile two shaped electric pulses with high time synchronization are input into the modulators respectively, which carries out high synchronization between the shaped optic pulse and the probe optic pulse. The scheme may be taken as a standby scheme of the present one in SGII. In the sixth chapter, the conclusion of the paper. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16520]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 高云凯. 基于孔耦合带状线的激光脉冲整形系统[D]. 中国科学院上海光学精密机械研究所. 2005. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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