高功率飞秒激光光谱展宽和三维光存储研究

【作者】 余娟；

【导师】 侯洵； 王屹山；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 光学工程， 2006， 硕士

【摘要】 飞秒激光的短脉冲和高辐射强度特性，及其在对物质进行处理过程中的非接触性和快速响应性，使得其在许多领域有着重要的应用价值，如超精细加工、微光子器件制造、医学精密手术、高密度三维光存储等。随着人们对极限条件下物质相互作用研究的逐渐深入，对激光脉冲的能量和脉冲宽度提出了更高的要求，使得人们不断的寻求获得超强超短激光脉冲的技术和手段。 本论文主要包括两方面内容，第一部分开展了基于LiF：F₂晶体色心产生机理以及在三维光存储应用中的实验研究；第二部分是利用中空光纤开展高功率飞秒激光光谱展宽理论及实验研究，为进一步压缩脉宽和获得高峰值功率飞秒激光打下基础。 与基于损伤机制的三维光存储相比，色心光存储由于写入光能量较低，读出方式与现有的光盘技术相兼容，而倍受人们的青睐。本论文第一部分根据实验中首次观察到LiF：F₂晶体在远红外飞秒激光脉冲作用下的发生色心类型转变的现象，定性的研究了其色心转变的机理，并在此基础上开展了三维光存储的原理性实验研究。 利用中空光纤的高损伤阈值特性和低色散特性，可以有效地传输高功率飞秒激光，同时利用其中非线性效应（主要是自相位调制，SPM）对高功率飞秒激光进行光谱展宽，从而通过进一步压缩技术可获得高峰值功率飞秒激光短脉冲。本文的第二部分在分析模拟中空光纤的模式特性以及非线性效应及色散特性基础上，开展了高功率飞秒激光在中空光纤的传输实验研究，耦合效率达50％以上，利用在中空光纤中填充惰性气体的方法实现高功率飞秒激光的光谱展宽，输出能量为220μJ，经傅里叶变换计算，展宽后的光谱可以支持6fs的脉宽。更多还原

【Abstract】 Femtosecond laser has many merits such as ultra-short pulse breadth, high irradiation intensity, and keeping clear of substance and fast response during processing matter . Based on those virtues, femtosecond laser pulse can be used many fields, for example, ultra-precision machining, the fabrication of micro- photonic devices, nano-operation in bioengineering and biatrology, and three dimensional optical storage. With the deep research on the interaction of matters under limit condition, pulse width desired is much shorter and intensity of laser needed is much higher, so technology and means which can produce ultra-short and high intensity laser pulse are sought.This dissertation include two contents: in section 1, the theoretic and experimental research on three-dimension optical data storage based on the conversion of color centers has been practiced; in section2, the theoretic and experimental research on spectrum-broaden using hollow fiber filled gas has been carried out, it is foundation to further compress pulse-width and obtain high intensity femtosecond laser pulse.Compared with other three-dimension optical data storage technology based on destroy mechanics, color-center optical storage is welcome because energy of its writing beam is lower and reading formation can be compatible with existent optical disc technology. In section 1 of this thesis, according to the phenomenon of the conversion of F₂ centers to F₃⁺ centers induced by IR pulse laser in LiF: F₂ crystal we find out firstly and the difference of fluorescence spectrum in the two centers, the qualitative analysis of this conversion is given, and the principle experiment of the color-center optical 3D data storage was realized.更多还原