飞秒激光在透明介质中诱导微结构的研究
文献类型：学位论文
| 作者 | 胡晓 |
| 学位类别 | 博士 |
| 答辩日期 | 2008 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 邱建荣 |
| 关键词 | 飞秒激光 金属纳米颗粒 自组装点阵 |
| 其他题名 | Microstructures Induced by Femtosecond Laser in Transparent Materials |
| 中文摘要 | 本论文主要报道了关于飞秒激光在晶体和玻璃中诱导微结构的研究，包括飞秒激光诱导玻璃中金属纳米颗粒的空间选择性析出，以及单束飞秒激光在晶体材料中诱导自组装点阵结构等内容。 贵金属纳米颗粒掺杂玻璃由于具有超快非线性响应和较高的非线性系数等性质，在光电设备的制造领域具有很好的发展前景。而在透明玻璃中空间选择性的诱导金属纳米颗粒的析出，对实现具有空间选择性功能的光电子器件的集成具有重要的应用价值。在本论文中，我们报道了通过飞秒激光的照射和随后的热处理， Ag+, Au3+共掺的硅酸盐玻璃中金银纳米颗粒的空间选择性析出，研究了金银纳米结构的光吸收特性以及飞秒激光的平均功率对Ag+, Au3+共掺硅酸盐玻璃光吸收性质的影响。采用金银离子共掺的硅酸盐玻璃，可以实现金银两种金属纳米颗粒的共同析出，但是析出的颗粒处于同一区域中。在硅酸盐玻璃中实现不同区域内不同种类金属纳米颗粒的析出还未见报道。本文中我们通过调整飞秒激光照射和热处理的实验步骤实现了在同一块玻璃样品的不同区域内金银纳米颗粒的分别析出，工艺简单，易于操作，在制备集成光学器件及双色三维玻璃内雕中具有重大意义。 另外为了更好的拓展贵金属纳米颗粒掺杂玻璃的应用和深入的探讨实验机理，我们研究了玻璃组成对金银纳米颗粒析出特性的影响。我们逐渐用MgO代替以往玻璃基质中的CaO，发现MgO的添加使得金银纳米颗粒的析出温度得到大大的降低，降低幅度达到100℃。我们还研究了MgO的添加对金属颗粒其他析出特性的变化，同时对机理进行了分析。 由于飞秒激光的超快超强特性，使得飞秒激光诱导微结构的研究充满了机遇，时有激动人心的新发现产生。2006年Kanehira报道了一种新现象：将单束光聚焦在硼酸盐玻璃内部某处，在聚焦点下方自发生长出了一条丝状结构，观察丝状结构的内部，发现了纳米量级周期排列的点结构。这种点阵制备方法有可能应用于二维或三维的周期微结构，甚至光子晶体的制备。在他们的实验基础上，我们实现了用单束聚焦激光在CaF2晶体中诱导自组装半周期微纳点阵，点阵的总的长度可以达到100微米或更长。我们还观察了点阵的结构参数和辐照条件的关系，特别是和激光聚焦点距离表面深度的关系：发现随着聚焦深度的增加，点阵的长度先增加，后减短。除了在CaF2晶体中诱导出准周期排列的点阵结构，我们在Al2O3晶体中也诱导出类似结构。我们发现规则的点阵结构的形成和激光聚焦点距离上表面的距离有很大关系。当激光脉冲能量确定的时候，对于某种特定的晶体，规则清晰的点阵也只在一个确定的聚焦深度范围内形成。我们用群速色散的理论结合不同材料的激光烧蚀阈值解释了在不同晶体中发现的规律。 在我们的实验中，我们发现除了聚焦点下方沿着激光方向的自组装点结构，另外还有一串点阵垂直于激光传输方向自发生成。我们在CaF2晶体材料中用单束激光实现了两串互相垂直的点阵的自发生成。这两串点阵在激光辐照的时候同时形成。这种技术有可能被应用于微光学器件以及光子晶体的制造，提高激光微加工的效率等。另外我们还发现当我们使用了油浸透镜来聚焦激光的时候，会在逆着激光传输的方向生长出自组装点阵结构。这种现象在硼酸盐玻璃中和氧化铝单晶中都得到证实。并且我们发现只有当使用的油浸透镜干燥（即不浸油）的时候，这种点阵才会逆向生长，而当使用浸油的透镜的时候，点串顺着激光的传输方向生长。对于这个现象的机理，我们还在探讨模拟中。 |
| 英文摘要 | This dissertation is focused on micro-fabrication in glasses and crystals using femtosecond laser, including space-selective precipitation of novel metal nanoparticles in glasses and self-organized microvoids in crystals. Glasses containing noble metal nanoparticles are expected as promising materials for ultrafast optical switches and optical circuits. Space-selective precipitation of novel metal nanoparticles by femtosecond laser irradiation will provide an important solution for the applications. Studies on the co-precipitation of silver and gold nanoparticles in Ag+, Au3+ co-doped silicate glasses by irradiation of femtosecond laser pulses were reported in this paper. The effects of average laser power and the annealing temperatures on the absorption properties of the sample were investigated, thus we realized controllable precipitation and dissolution of Ag and Au nanoparticles in Ag+ and Au3+ co-doped silicate glass sample. Then a new method was proposed for separate precipitation of Ag and Au nanoparticles in different areas of the same sample through femtosecond laser irradiation and further annealing; different colors were obtained in the same glass. We also studied the laser dissolution of Ag and Au nanoparticles in the Ag+ and Au3+ co-doped silicate glass. In the end, we studied the effect of MgO on the precipitation behavior of Ag and Au nanoparticles in femtosecond laser irradiated glass. Precipitation temperature of Ag and Au nanoparticles was dramatically decreased by adding MgO into the glass host materials. Some other characteristics of these Au and Ag nanoparticles influenced by the addition of MgO were also studied. The femtosecond laser, with extremely high electric field, is an ideal tool to fabricate micro-photonic functional elements in transparent materials. Recently, Shingo Kanehira obtained periodic nanovoid structures in borosilicate glass using femtosecond laser. The voids were formed spontaneously with the laser beam focused at a fixed point. We report the self-formation of quasi-periodic void structure with total length of several hundred micrometers inside CaF2 crystal. The quasi-periodically lined voids were formed spontaneously after the irradiation of a single focused femtosecond laser beam without moving the focal point. The structure parameters of the void array are dependent on the laser focal depth in the sample. We also reported on the femtosecond laser induced self-organized void array inside Al2O3 crystals. It is found that regular voids can only be fabricated near the sample surface, which is different from the situation in CaF2 single crystal which we reported before. The possible mechanism of the phenomena was discussed. In our experiment, except the void array grown below the focal point which had been reported before, we found another void array grown vertical to the laser propagation direction. This result has potential application in the fabrication of integrated micro-optic elements and photonic crystals. The possible mechanism of the phenomenon was proposed and verified experimentally. Being different with the report before, we also found in our experiments that: in borosilicate glasses, the void array grew oppositely to the laser propagation direction when the laser beam was focused by an oil immersion lens without oil immersed. This phenomenon was also found in crystal samples. The mechanism was discussed briefly and the simulation is going on. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15244]  |
| 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 | 胡晓. 飞秒激光在透明介质中诱导微结构的研究[D]. 中国科学院上海光学精密机械研究所. 2008. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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