用于真空在线测量的离轴非球面结构反射差分光谱仪设计与实现  

Design and implementation of an off-axis aspheric mirror structured reflectance difference spectrometer for in-situ vacuum application

作　　者：徐臻圆[1] 傅星[1] 张一帆[1,2] 谢鹏飞[1] 胡春光[1] 胡小唐[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]密歇根大学机械工程系,安娜堡48109

出　　处：《光电子．激光》2013年第10期1960-1966,共7页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61008028);全国博士学位论文作者专项资金(201140);天津市应用基础及前沿技术研究计划JCJBJC25700)资助项目

摘　　要：基于旋转补偿器的反射差分光谱（RC—RDS）技术是具有亚单层光学灵敏度的高精度表面表征方法，其全光谱快速测量性能，特别适合在线检测。为满足真空在线测量的应用需求，综合考虑使用空间、工作距离、光束直径、光谱宽度和通光率等限制因素，提出了基于离轴抛物（OAP）反射镜的光学测头设计方案，构建的测试样机实现了有效工作距离大于50cm、光斑直径小于6．5mm和光谱范围涵盖280～825nm等性能。实验研究了超高真空环境Cu（110）样品在退火处理中的RDS，仪器详细记录了信号随温度的演变过程，测量精度优于3×10-4，表明新方案满足真空环境下表面高灵敏光学测试的需求。Rotating-compensator based reflectance difference spectroscopy （RC-RDS） is a versatile tool, which allows an RD spectrum at one time within several seconds and offers a sub-monolayer resolution for surface optical characterization. Thereby it is suitable for in-situ application. But there are many prob- lems for the RC-RDS based in-situ measurement in the vacuum environment,i, e. ,the restrictions on the working space, the measuring distance from the front of the optical head to the sample, the beam size on the sample,the spectrum range, and the optical transparency of the total system. A new design for the optical head to overcome these problems is proposed, where an off axis parabolic mirror is adopted for adjusting the beam in a compact and effective way. For the new optical head,a working distance of more than 50 cm,a focused beam size on the sample of less than 6.5 mm in diameter,and a spectral range of 280-825 nm are achieved. An experiment for monitoring the RD spectra of a Cu（110） sample in ultra- high vacuum environment was performed during an annealing process. And the evolution of the RD sig- nal was perfectly recorded in a set of 512 spectra. The results with a measurement precision of 3 X 10-4 indicate the good performance of the new design for the vacuum application.

关 键 词：反射差分光谱(RDS)技术 表面光学表征 真空在线测量 离轴抛物(OAP)反射镜 

分 类 号：TH744.2[机械工程—光学工程] O433.1[机械工程—仪器科学与技术]