摘要3μm波段位于水的吸收峰，同时包含大量气体分子的特征吸收谱，该波长范围内的激光在军事和医疗领域均有广泛的应用前景。掺Er3+激光器是获得3μm波段激光输出的有效途径之一。本文主要研究了掺Er倍半氧化物透明陶瓷的能级结构和光谱特性，以及LD端面泵浦Er3+掺杂倍半氧化物陶瓷激光器的热透镜效应。具体内容如下：50165

首先，本文介绍了Er3+离子与3μm激光振荡相关的能级，并计算了Er:Lu2O3各能级之间可能存在的泵浦吸收波长、激光发射波长，以及各斯塔克子能级粒子数分布的玻尔兹曼系数。结合光谱实验数据，探讨了3μm掺饵倍半氧化物陶瓷激光器波长输出的动力学特性。

其次，基于端面泵浦Er3+掺杂固体激光器的实际特点（激光陶瓷周边恒温冷却、通光面绝热），建立了三维各项同性热传导模型。利用有限差分法计算出激光陶瓷中的温度分布，晶体端面热膨胀量，以及由此所产生的光程差。在此基础上，研究泵浦光斑大小、泵浦功率、陶瓷尺寸以及水冷温度等实验因素对激光热透镜大小的影响。在相同实验条件下，通过对比LD端面泵浦Er:Lu2O3透明陶瓷激光器和传统3μm波段Er:YAG晶体激光器热透镜的大小，表明Er:Lu2O3倍半氧化物透明陶瓷是一种新型、优质的高功率3μm波段中红外激光材料。

该论文有图14幅，表10个，参考文献15篇。

毕业论文关键词：能级结构  3μm激光  倍半氧化物  热效应

The Research of Er-doped Sequioxides Transparent Ceramic Lasers

Abstract

Laser sources operating around 3-μm waveband have recently attracted considerable attention because of their emission lines coincide with numerous molecular fingerprints, relating to strong rotational-vibration absorption of molecular gases. Diode pumped Er solid-stated lasers operating in the mentioned spectral region are promising candidate sources for using in the laser military and medical science. In this thesis, energy structure and spectral properties of the Er-doped sesquioxide ceramics was first studied. And then, thermal lensing effects of the LD end-pumped Er-doped sesquioxides were systematic investigated. Specific content is as follows:

Part one has firstly introduced the energy states related to the 3-μm laser transition. And then, possible existence of the pump wavelength, laser wavelength, and the Boltzmann factors of the distribution of the populations in the energy states were calculated, respectively. At last, dynamics of the laser output was discussed in combination with the spectral experimental date.

Part two has constructed a 3-D isotropic thermal conduction model for the LD end-pumped Er-doped solid state lasers by considering the features of the laser experiment. The finite difference method was employed in solving the Possion equation with fixed boundary conditions. The thermal distribution in the laser ceramic, the thermal induced length changes of the laser gain medium, and the resulted optical path difference (OPD) was calculated respectively. Consequently, the focal length of the LD end-pumped Er solid state lasers were obtained at different pump spot, pump power, ceramic size, and temperature of the heat sink, respectively. The calculated results shows that the Er:Lu2O3 transparent ceramics is an promising candidate laser gain medium for high power laser operation in the 3-μm waveband.

Key words: Energy level structure   3μm laser   Sesquioxides   Thermal effects

目 录

摘 要 I

Abstract II

目 录 III

1绪论 1

1.1研究背景