SESAM被动调Q Yb:YAG薄片激光器实验研究
文献类型：学位论文
| 作者 | 尹霞 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 陈卫标、孟俊清 |
| 关键词 | 激光器 被动调Q 可饱和吸收镜 Yb:YAG 薄片 |
| 其他题名 | Study on SESAM passively Q-switched Yb:YAG microchip laser |
| 中文摘要 | 由被动调Q激光器产生的激光脉冲，尤其是亚纳秒脉冲，具有高脉冲能量、高峰值功率，在激光遥感、微机械加工、非线性光学研究、医疗、光通信、环境监测等领域得到了广泛的应用。可饱和吸收镜(SESAM)作为可饱和吸收体的同时，还可以作为被动调Q激光器谐振腔中的一个腔镜，因此可以缩短谐振腔的腔长，从而可以获得更窄的被动调Q激光脉冲。与掺Nd3+离子的激光晶体相比，Yb:YAG晶体具有量子损耗小、受激发射截面大、掺杂浓度高、荧光寿命长、吸收光谱比较宽等优点，作为被动调Q激光器的增益介质，易于获得稳定、高脉冲能量、高峰值功率的激光脉冲。 基于以上原因，本文围绕SESAM被动调Q Yb:YAG薄片激光器进行了一系列理论和实验研究，包括以下几个方面： 1) 通过调研文献，在SESAM被动调Q薄片激光器速率方程的基础上，分析了SESAM被动调Q Yb:YAG薄片激光器的阈值泵浦功率、激光脉冲宽度、单脉冲能量及峰值功率等激光性能的影响因素，并由此完成了激光器的参数设计。 2) 搭建了Yb:YAG薄片激光器连续输出的实验装置，完成了当增益晶体长度分别为100m、200m时的连续光输出实验。通过实验，当晶体长度为200m时得到了光-光效率为31%的连续光输出。 3) 采用“SESAM-Yb:YAG-耦合输出镜”三明治结构，完成了不同调制深度、不同晶体长度的SESAM被动调Q Yb:YAG薄片激光器实验，当SESAM调制深度为5%，Yb:YAG晶体长为100m时，获得了脉冲宽度为217.8ps的激光脉冲，据我们所知，这是Yb:YAG作为增益介质取得的最窄的被动调Q脉冲。 4) 为了能获得更窄的激光脉冲，研究了增益晶体和SESAM胶合方式下，SESAM被动调QNd:YVO4薄片激光器实验，获得了脉宽为86.5ps的激光脉冲，与脉宽理论值完全相符。 |
| 英文摘要 | Sources of passively Q-switched lasers that can generate pulses with high energies and peak powers are desirable for laser ranging, micromachining, nonlinear studies, medical surgery, optical communications, pollution monitoring and so on. The semiconductor saturable-absorber mirror (SESAM) can be a resonator mirror while as a saturable absorber. Thus it allows shorter cavity length and therefore the shorter pulse width. Compared with laser crystal doped with Nd3+, Yb:YAG has lower quantum defect, a relatively low laser cross-sections, higher doping concentration, longer fluorescence lifetime, excellent thermal properties and broader absorption brands. So as a gain media, Yb:YAG is advantageous to get stable laser pulses with higher energies and peak powers. Due to the above reasons, this thesis are mainly centered on the SESAM Q-switched Yb:YAG microchip laser and related theoretical and experimental results. The detailed contents involved are as follows: 1) On the basis of literature research, the rate equations of SESAM Q-switched microchip lasers are analyzed, and influence factors of such laser parameters as pump threshold, pulse width, pulse energy, peak power and so on are studied. According to the results, the design of the experiments is finished. 2) The setup of Yb:YAG microchip laser for CW operation is built. 100m，200m-length of Yb:YAG is as the gain media during experiments. The maximum optical efficiency of 31% is gained when the gain media is 200m long. 3) Employing a setup of a Yb:YAG microchip crystal sandwiched between a SESAM and a output coupler, Q-switched pulses are respectively obtained when the crystals are with different lengths, and the SESAMs are with different modulation depths. To our knowledge, the shortest Q-switching pulses of 217.8ps from a Yb:YAG microchip laser are got with a 100m-length gain media. 4) In order to receive shorter pulses, SESAM Q-switched Nd:YVO4 microchip laser with items bonded by glue is studied. Pulses of 86.5ps are obtained, which completely accords with the theory value. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16758]  |
| 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 | 尹霞. SESAM被动调Q Yb:YAG薄片激光器实验研究[D]. 中国科学院上海光学精密机械研究所. 2013. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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