基于GSA-ESA双波长抽运Er:Lu2O3晶体3μm激光特性研究

项目名称： 基于GSA-ESA双波长抽运Er:Lu2O3晶体3μm激光特性研究

项目编号： No.61308020

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 李涛

作者单位： 山东大学

项目金额： 25万元

中文摘要： 中红外3μm波段处于水分子强吸收带内，在激光医疗、遥感探测、光参量放大等领域有广泛的应用前景。Er3+是产生3μm激光的主要激活离子，但其下能级（4I13/2）寿命较长（~12 ms），易导致激光再吸收甚至猝灭，激光量子亏损较高（~65%），传统的抽运方式难以获得高效率激光输出。为此，本项目以低声子能量、高热导率的Er:Lu2O3晶体为研究对象，构建GSA-ESA双波长抽运理论模型，分析Er3+能级跃迁动力学过程及其对激光输出特性的影响。利用Er3+离子下能级寿命较长的特点，结合激发态吸收机理，通过双波长抽运技术，实验研究3μm激光连续运转特性。通过本项目的实施，有效减少Er:Lu2O3晶体3μm激光下能级粒子数，弱化多声子弛豫所产生的冗余热影响，实现低阈值、高效率激光输出，为进一步实现高功率中红外激光运转提供理论基础和技术指导。

中文关键词： Er:Lu2O3 晶体；双波长抽运；中红外激光；激发态吸收；

英文摘要： Bing the starting range of middle infrared band, 3 μm lasers, are the limitting wavelength which can be efficiently attained by solid state lasers. Their field of applications is manifold: in medicine, in gas-sensing systems, as well as for pumping optical parametric oscillators. Erbium is the most interesting active ion in 3 μm lasers, however due to the prety high quantum defect efficiency (~65% to ~73% under 790 nm (4I15/2→4I9/2) or 974 nm (4I15/2→4I11/2))and the shortage of laser diod pump sources with long wavelength emission, the efficiency of 3 μm lasers is far wawy from near infrared lasers. In Erbium active ion, the laser levels system is quite complex, the long lifetime of the lower laser level (4I13/2) induces high population density of this level during laser operation and thus increases the laser threshold and terminates the laser transition. An efficiente solution to this prolem is to decrease the population deposition on lower laser level (4I13/2), which can be easyly realized by using exite state absorption (ESA) pumping cooperating with ground state absorption，named "GSA-ESA daul-wavelength linkage pumping scheme" in this propose. Conventional excitation of laser media raises individual atoms or ions directly to energy levels above the emitting level. However, as we show here, energy states lyi

英文关键词： Er:Lu2O3 crystal；Dual-wavelength linkage pumping；MIR lasers；Excited-state absorption；