激光辐照VO_2薄膜温度场分布及透射特性研究  

Temperature Field Distribution and Transmittance Characteristics of VO_2 Films Irradiated by Laser

作　　者：刘志伟 路远 侯典心[1,2,3] 邹崇文 LIU Zhi-wei;LU Yuan;HOU Dian-xin;ZOU Chong-wen(Electronic Countermeasures Institute of National University of Defense Technology,Hefei 230037,China;Infrared and Low Temperature Plasma Key Laboratory of Anhui Province,Hefei 230037,China;State Key Laboratory of Pulsed Power Laser Technology,Hefei 230037,China;National Synchronous Radiation Laboratory of University of Science and Technology of China,Hefei 230037,China)

机构地区：[1]国防科技大学电子对抗学院,安徽合肥230037 [2]红外与低温等离子体安徽省重点实验室,安徽合肥230037 [3]脉冲功率激光技术国家重点实验室,安徽合肥230037 [4]中国科学技术大学国家同步辐射实验室,安徽合肥230037

出　　处：《发光学报》2018年第11期1604-1612,共9页Chinese Journal of Luminescence

基　　金：脉冲功率激光技术国家重点实验室主任基金(SKL2013ZR03)资助项目~~

摘　　要：为了探究VO_2薄膜受激光辐照的温度场分布,以及1 064 nm激光直接辐照100 s内至相变的激光功率密度阈值,并比较近红外和中红外波段透过率调制特性差异。首先基于COMSOL建立了薄膜受激光辐照的模型并进行了温度场仿真,然后分别测试了薄膜正反面被不同功率密度的1 064 nm激光辐照100 s内激光透过率随时间响应特性。实验中的VO_2薄膜利用分子束外延法在Al_2O_3基底上制备得到。仿真结果表明,激光功率密度为25 W獉mm^(-2)时,50 nm厚薄膜在被辐照1 ms时间内即达到相变温度。经激光辐照实验发现:50 nm厚的VO_2薄膜正反面受1 064 nm激光直接辐照100 s内至相变的功率密度阈值分别为4.1 W獉mm^(-2)和5.39 W獉mm^(-2)。30 nm厚VO_2薄膜对1 064 nmn激光的透过率调制深度约为13%,对3 459 nm激光透过率调制深度约62%,说明VO_2薄膜对近红外透过率调制特性不明显。In order to explore the temperature field distribution and power density threshold of 1 064 nm laser that irradiate film and make it phase change in 100 s,and to compare the difference between the transmittance modulation characteristics in the near infrared and mid-infrared band,a model of laser irradiation was set up and the temperature field was simulated.Then,the 1 064 nm laser transmittance response characteristic with time was tested in the front and back face of VO2 film with different laser power density in 100 s separately.VO2 thin films in the experiment were prepared by molecular beam epitaxy on Al2O3 substrate.Simulation results show that the film reaches the phase-transition temperature in 1 ms with 25 W.mm^-2 laser power density.It is found that the laser power density threshold is 4.1 W.mm^-2 and 5.39 W.mm^-2 when irradiating the front and back face of the VO2 thin film with 50 nm thickness respectively.The transmittance modulation depth of 1 064 nm is approximately 13%of VO2 thin films with 30 nm thickness.However,compared with 62%for 3 459 nm laser,the transmittance modulation characteristic in near infrared is not obvious for VO2 thin films.

关 键 词：VO2薄膜 分子束外延 COMSOL仿真 温度场分布 透过率调制深度 相变功率密度阈值 

分 类 号：O434.14[机械工程—光学工程]