1.State Key Laboratory of Infrared Physics， Shanghai Institute of Technical Physics， Chinese Academy of Sciences， Shanghai 200083， China;2.Department of Physics， Shanghai Normal University， Shanghai 200234， China;3.Shanghai Engineering Research Center of Energy-Saving Coatings， Shanghai 200083， China;4.Shanghai Research Center for Quantum Sciences， Shanghai 201315， China;5.University of Chinese Academy of Sciences， Beijing 100049， China;6.School of Physical Science and Technology， ShanghaiTech University， Shanghai 201210， China;7.Nantong Academy of Intelligent Sensing， Nantong 226000， China
This work was fumded by Natuonal key R&D Program of China （2021YFA07115500） and National Notural Science Foundation of China （11874376）.
The optical constants （refractive index and extinction coefficient） accuracy of thin films directly affects the properties of designed and fabricated optical devices. Most of the determination methods of optical constants are complex and cannot be applied during the film depositing process. In this paper， an optical constants determination method of thin films on-site is proposed. By monitoring the transmittance of depositing materials， this method can rapidly and accurately determine the optical constants on-site. For demonstration， the near-infrared optical constants of high-absorption material Si， low-absorption material Ta2O5 and ultra-low-absorption material SiO2 are obtained as n=3.22， k=4.6×10-3， n=2.06， k=1.3×10-3 and n= 1.46， k=6.6×10-5 respectively by this method. It reveals that this method is suitable for determining both strong and weak absorption materials’ optical constants. It provides an effective way for precisely determining optical constants on-site， which is meaningful for the design and fabrication of high-quality optical devices.
XIE Mao-Bin, WU Zhi-Yong, CUI Heng-Yi, ZHAO Xin-Chao, XUAN Zhi-Yi, LIU Qing-Quan, LIU Feng, SUN Liao-Xin, WANG Shao-Wei. On-site determination of optical constants for thin films[J]. Journal of Infrared and Millimeter Waves,2022,41(5):888~893Copy