单频1572nm参量振荡光谱纯度测量及PPLN晶体OPO特性研究
文献类型：学位论文
| 作者 | 姜佳欣 |
| 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 | 朱小磊 |
| 关键词 | 光参量振荡器 光谱纯度 吸收池 种子注入 准相位匹配 周期极化铌酸锂 |
| 其他题名 | Study on Spectral Purity of Single Frequency 1572nm Optical Parametric Oscillator and Characteristics of PPLN Crystal OPO |
| 中文摘要 | 采用星载积分路径差分吸收（IPDA）激光雷达对大气CO2浓度进行测量，是一种高精度主动遥感探测技术，种子注入单频脉冲光参量振荡器（OPO）是实现差分吸收雷达激光光源的重要技术手段。单频脉冲光参量振荡器的光谱纯度将直接影响雷达系统的测量精度。就种子注入单频脉冲激光光源而言，光谱纯度表征在其输出光谱中，种子波长成分所占的比例，可以综合反映脉冲激光的输出线宽和频率稳定性等光谱特性。 论文研究工作针对种子注入单频1.57μm脉冲OPO振荡器，建立了初步的理论仿真模型，讨论了种子注入功率、相位匹配条件、腔长失谐、泵浦源性能等因素对光谱纯度的影响。分析了吸收池的长度、充气压强等参数对系统测量精度的影响，确定了所需器件的型号，并给出了误差分析，最终搭建了一套用于测量单频1.57μmOPO光谱纯度的测量系统。实验结果表明，当种子注入功率26mW、单脉冲能量1.1mJ时，OPO输出的光谱纯度达到99.9%。通过分析现有装置测试过程中随机性和偶然性偏多的现象，提出改进意见，达到精确测量脉冲激光器输出光谱纯度的目的，为研制集成化自动测量平台提供技术支持。 3~5μm中红外波段覆盖了许多重要的分子特征谱线，高效率、窄线宽脉冲全固态中红外激光辐射源在红外对抗、激光测距、激光雷达、空间通信以及医学诊断和治疗方面有广阔的研究价值和应用前景。 基于准相位匹配技术，探究了周期极化铌酸锂晶体（PPLN）用于产生中红外波段OPO的特性。首先搭建了直腔OPO，对比了不同腔镜曲率半径、腔镜透过率和聚焦透镜焦距的输出特性，实验结果表明，腔镜曲率半径230mm、输出镜透过率50%时，OPO阈值约40mW，总输出功率的斜率效率为40.1%，光-光转换效率最高可达37.4%，其中，3.3μm波段的光的斜率效率为16.8%，光-光转换效率最高可达17%。测试了OPO输出的激光光谱和PPLN晶体的温度调谐特性，分析了逆转换和其他非线性效应现象。以此为基础，从稳定性和模式匹配等方面设计了PPLN晶体环形腔OPO，实验表明，在OPO自由运转状态下，环形腔总输出功率的斜率效率为25.7%，光-光效率最高为24%，3.3μm波段激光的斜率为10.4%，光-光效率最高为10.2%。 通过搭建初步实验装置，探索新的实现高功率、窄线宽、宽调谐、频率稳定中红外激光输出技术路线和方案，为研制全固态、紧凑型和小型化的高效率中红外激光辐射源提供技术依据。 |
| 英文摘要 | Utilizing integrated path differential absorption(IPDA) lidar to measure atmospheric CO2 concentration is an active remote sensing technology with high precision. Injecting-seeded single-frequency pulsed optical parametric oscillator (OPO), whose spectral purity effects the accuracy of lidar system dramatically, is an important technique to realize differential absorption lidar(DIAL). In terms of injecting seeded single frequency pulsed OPO source, spectral purity demonstrates the ratio of seed mode energy to the whole pulse energy, which presents a comprehensive projection of spectral performances such as linewidth and frequency stability. In connection with 1.57μm injecting seeded OPO, a preliminary theoretical simulating model is established to analyze factors influencing spectral purity, including seed injecting power, phase matching condition, cavity length detuning and pump source. Influences of absorption cell length and pressure on system precision are analyzed. Select the device type according to theoretical calculation. Error analysis is conducted. Finally a measuring system is designed and built up. Experimental results show that spectral purity of injecting seeded OPO can achieve 99.9% when seeder injecting power is 24mW and OPO output energy is around 1.1mJ. Through analyzing the random error and contingency of existing device, improvement suggestions are put forward in order to achieve the purpose of measuring the spectral purity of pulsed OPO accurately. This research work can provide technique support for integrated automatic measurement platform of spectral purity . 3~5μm mid-infrared region covers many important moleculars’ characteristic spectral line. All solid-state mid-infrared pulsed laser radiation source with high efficiency and narrow linewidth is of great interest in many applications, such as infrared countermeasure, laser ranging, lidar detection, space communication, medical diagnosis and treatment. Based on quasi-phase-matching technology, characteristics of mid-infrared OPO applying periodically poled lithium niobate(PPLN) crystal are explored. First, a linear OPO is developed. Different curvature radius of mirror, different mirror transmittance and different focal lengths of focusing lens are compared in order to get better output characteristics. Results show that in condition of 230mm curvature radius and 50% mirror transmittance, the threshold is 40mW while the slope efficiency of all light output power is 40.1% and the maximum optical-optical efficiency is 37.4%. Conversion efficiency of 17% from pump to 3.3μm idler and slope efficiency of 16.8% are achieved. Temperature tuning characteristics of PPLN and laser output spectrum are measured. Phenomena of inverse conversion and other nonlinear effects are analyzed. On this basis, four-mirror ring cavity is designed from the aspect of stability and mode matching. Experimental results show that the slope efficiency of all light output power is 25.7% and the maximum optical-optical efficiency is 24% for free running OPO. Conversion efficiency of 10.2% from pump to 3.3μm idler and slope efficiency of 10.4% are achieved. A first-step experimental device is developed to investigate the function of seed injecting on narrowing linewidth. New technical routes to realize mid-infrared laser output with high power, narrow linewidth, widely tune and high frequency stability remain to be explored. It provides technical support for researching compact miniaturized all solid-state mid-infrared pulsed laser radiation source. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16890]  |
| 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 | 姜佳欣. 单频1572nm参量振荡光谱纯度测量及PPLN晶体OPO特性研究[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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