固态染料可调谐激光器研究

【作者】 任杰；

【导师】 洪治；

【作者基本信息】 浙江大学 ， 光学工程， 2004， 硕士

【摘要】 染料激光器因具有波长调谐范围宽、输出功率高、吸收和增益容易控制等优点，在医疗、遥感、光谱分析等领域得到了广泛应用。与液体染料激光器相比，固态染料激光器结构紧凑、应用简便、无污染、成本低，因此染料固态化是人们一直以来研究的目标。目前，固态染料的工作寿命及损伤阈值已经有了很大提高，染料的光学均匀性、可加工性能都有了很大的改善，但距离实用还有一定的距离。 为了提高固态激光染料的力学性能、热性能及光学性能，研究人员对各种制备方法进行了广泛的研究。近来研究较多的是玻璃基质无机有机复合激光染料，通过溶胶—凝胶法，将有机激光染料均匀地掺入固态基质中，再利用适当的有机改性，就能有效提高材料各方面的性能。 本论文首先对可调谐激光器的发展、研究进展及应用进行了简单回顾，然后对固态激光染料的特性、制备进行了分析和讨论，进而对可调谐染料激光器的调谐原理进行了理论上的分析和讨论。在此基础上，对由浙大材料系提供的、通过溶胶-凝胶(sol-gel)过程，利用新型分步合成方法制备的以VTES为先驱体P567掺杂固态染料样品，进行了激光宽带辐射特性及寿命实验；设计了不同谐振腔型的固态染料可调谐激光器，并进行了实验研究，对调谐腔的工作参数及输出特性(如调谐范围、斜效率、阈值、输出线宽等)进行了理论分析及实验对比。 在激光宽带辐射实验中，获得了7nm(FWHM)的激光输出，斜效率达69％。在染料寿命测试中，38000个泵浦脉冲后，输出能量降到初始输出的50％，已知报道的P567掺杂固态染料寿命也均在10~4量级。在腔镜耦合输出的可调谐激光器实验中，输出调谐范围超过30nm，此结果与报道的P567固态染料调谐范围相近；在光栅零级输出实验中，激光输出调谐范围近70nm，此结果在已知报道的P567固态染料激光调谐范围中是最宽的。更多还原

【Abstract】 Solid-state dye lasers exhibit some attractive features as compared with conventional liquid-dye lasers, such as lack of toxicity and flammability, compactness and low-cost gain medium which, in addition to being an essentially maintenance-free system, make them suitable for applications in field such as medicine, remote sensing and spectroscopy. The development of tunable solid-state dye lasers in which a polymer or glass host medium is doped with an appropriate dye is an area of active research.To achieve better thermal properties, such as higher thermal conductivity, lower thermal expansion, better mechanical properties and higher damage threshold, both organic polymers and silica-based inorganic polymers obtained by the sol-gel process have been used as hosts for solid dyes. The low-temperature sol-gel process allows the incorporation of organic dyes into silica gel inorganic glasses, resulting in relatively photostable materials with acceptable laser efficiencies. Nevertheless, new modified polymers have been obtained recently with thresholds of damage by laser radiation as high as those of the inorganic materials, and with higher stabilities than those of the silica gels under the same experimental conditions.This thesis reviewed the development of tunable lasers, analyse the character and preparation of laser-dye, and introduce the theory of turnable lasers. Base on analysis and research, using the solid dye samples made by a stepwise synthesis technique through a sol-gel process, some experiments were done. Laser dye doped in the sample is pyrromethene 567. Longitudinally pumped tunable solid-state dye lasers using intra-cavity grating were established with Q-switched frequency-doubled Nd:YAG laser pumping source.With the cavity of output from zero-order diffractive beam, tunable range of about 70nm from 543-610nm had been achieved, and the highest slope efficiency of 17% was obtained at 583nm wavelength. While using the cavity of output from a coupling mirror, tunable range of over 30nm from 553-585nm was obtained, and the更多还原