多频调制前端系统的光谱控制技术研究
文献类型：学位论文
| 作者 | 陈醉雨 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 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 | 多频调制 幅频效应 光谱补偿 光谱检测 |
| 其他题名 | Research on frequency controlling technology in multiple phase modulation injection system |
| 中文摘要 | 随着大型高功率激光器的发展，针对于激光装置的各组成部分的新技术也得到了不断推进。在高功率激光装置中，一个困难点是在压缩时，要保持高度球形对称，束匀滑技术是减少由高能量的激光束所产生的空间照明不均匀性的方法，但在实施过程中，由于色散及光谱透过振幅不一致等原因，会产生幅频转换现象。为了抑制幅频转换效应，本文围绕光谱补偿与光谱检测技术展开，目的是设计一套光谱补偿装置以期在前端系统阶段预补偿光谱函数，并设计一套光谱检测装置来辅助检测并查看补偿效果。本文内容包括： 1.提出一种新型的利用液晶结合双折射晶体的光谱整形方法，实现了中心波长调节和幅度调节的解耦控制，并搭建一套基于此方法的光谱补偿装置。设计相应补偿函数，利用正弦函数进行补偿，通过配合使用双折射晶体和液晶调制器，可在45°的范围内调整双折射晶体的角度，其中心波长幅值可以在0至30dBm的范围内调整。通过改变液晶调制器的加载电压，可以使补偿函数中心波长在1051.5-1054.5nm内自由调整。 2.完成一套单次测量、高分辨率光谱检测系统，系统测试的中心波长1053nm，量程1.2nm，分辨率小于5pm。根据衍射光栅性质以及光谱仪的基本构型，针对于多频调制前端系统的光谱特点，对检测装置各参数进行有针对性的设计。本装置使用三块光栅实现四次衍射的方案，最终每像素的采样分辨率为0.668pm；检测结果由CCD接收，单次测量即可确定光谱分布，实现快速准确的检测。 3.完成了基于光谱预补偿方案的幅频调制抑制的在线实验验证。种子源输出激光的中心波长1053nm、光谱调制带宽0.7nm，并采用了新型的光谱预整形，最终经过增益为70dB的再生放大后，输出波形的幅频效应幅值~11％，而未补偿直接放大的结果为36%。 |
| 英文摘要 | With the development of high-power lasers, the new technology in the laser device has been steadily advancing. In the high-power laser device, it is very difficult to keep highly spherical symmetry during the compressing process. Beam smoothing technique is a way to reducespatial non-uniformity of the illumination generated by a high energy laser beam. But in the implementation process, the dispersion and spectral amplitude non-uniformly passing the device will produce FM-to-AM phenomenon. In order to decrease the amplitude-frequency conversion effect, this thesis focuses on spectral compensation and spectroscopy techniques, aiming to design a set of spectrum compensation device in multiple phase modulation injection system and a spectral detection device to assist in detecting as well as viewing the compensation effect. This thesis mainly consists of the following two sections: 1.A new spectrum shaping method that makes a combination of birefringent crystal and liquid crystal is defined to compensate FM-to-AM effects, which can adjust center wavelength and amplitude independently. Using sinusoidal compensation function, with the coordinated utilization of a birefringent crystal and a liquid crystal modulator, adjusting the crystal angle in the range of 45 °, the center wavelength could be reduced in the magnitude of the range from 0 to 30dBm. By changing the voltage of the liquid crystal, the center wavelength could be adjusted within 1051.5-1054.5nm freely. 2.A high-resolution spectrum detector is designed, which can show frequencies’ position singly measured. The tested system's wavelength is 1053nm, with a measured range of 1.2nm and resolution less than 5pm. For multi-frequency modulation spectrum characteristics in multiple phase modulation injection system, this spectral detector fits well. Because of using three gratings, it can get very high resolution. The final result can achieve 0.668pm per pixel and reduce FM-to-AM effects effectively with the spectrum compensation device. 3.A scheme to reduce FM-to-AM effects based on spectrum pre-compensation tested online is completed. For seed source output center wavelength 1053nm, spectral modulation bandwidth of 0.7nm, by using a new pre-shaping of the spectrum, eventually for the regenerative amplifier with the gain of 70dB, the output FM-to-AM magnitude could be controlled within 11% by this compensation system, while the uncompensated result is 36%. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16903]  |
| 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 | 陈醉雨. 多频调制前端系统的光谱控制技术研究[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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