膜厚监控系统准直聚焦耦合光路的研制  

Development of collimated focus coupled optical path for film thickness monitoring system

作　　者：谢海峰 付秀华[1,2] 董所涛 石澎[3] 任松林 杜昕 王由德 XIE Haifeng;FU Xiuhua;DONG Suotao;SHI Peng;REN Songlin;DU Xin;WANG Youde(College of Optoelectronic Engineering,Changchun University of Science and Technology,Chang chun 130022,China;Zhongshan Institute of Changchun University of Science and Technology,Zhongshan 528436,China;Zhongshan Torch Polytechnic,Zhongshan 528436,China;Guangdong Changli Jingxun Optoelectronics Technology Co.,Zhongshan 528436,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]长春理工大学中山研究院,广东中山528436 [3]中山火炬职业技术学院,广东中山528436 [4]广东长理精讯光电科技有限公司,广东中山528436

出　　处：《光学精密工程》2025年第1期25-36,共12页Optics and Precision Engineering

基　　金：中山市引进创新团队项目(No.CXTD2023008);中山市社会公益科技研究项目(No.2022B2005)。

摘　　要：针对直接式光学膜厚监控系统中卤素灯光源发散和探测器接收信号幅值弱,导致短波波段监控精度差,并且制备窄带滤光膜(带宽<5 nm)监控误差大引起光谱矩形度差等问题,通过分析HLX64623卤素灯的光强分布和光纤耦合原理,根据镀膜机的结构参数设计准直聚焦耦合光路系统的初始结构,通过采用非球面U型反光镜结构和自由曲面透镜实现发散光源的准直以及光信号聚焦与光纤耦合,利用Zemax软件以基板和光纤接收端面上的辐照强度和光斑尺寸为优化目标进行迭代优化,相比于独立光源结构,优化后基板辐照强度提高了147%,光纤接收端辐照强度从0提高到1.53%。将准直聚焦耦合光路系统安装在镀膜机上进行测试,相比独立光源信号强度提高了362.3%,信噪比提高了91.9%,通过制备365 nm带宽10 nm的窄带滤光膜,连续镀制三炉的中心波长偏移量在1 nm以内,半高宽均为10 nm。实验结果表明,该装置可实现对近紫外到可见近红外波段高精度窄带滤光膜的稳定监控.To address the limitations of current direct optical film thickness monitoring systems,including the dispersion of halogen lamp light sources,weak detector signal amplitudes,and poor monitoring accura-cy in the short-wave band,as well as the spectral non-rectangularity-induced errors in the fabrication of nar-row-band filter films(bandwidth<5 nm),this study proposes an innovative optical system design.By an-alyzing the intensity distribution of the HLX64623 halogen lamp and the principles of optical fiber coupling for signal reception,an initial structure for a collimated focusing coupled optical system was developed based on the structural parameters of the coating machine.The design incorporates an aspheric U-type re-flector and free-form surface lenses to achieve collimation of the dispersive light source,focusing of optical signals,and efficient optical fiber coupling.Using Zemax software,the system was iteratively optimized with the irradiance and spot size on the substrate and the optical fiber receiving end as key objectives.After optimization,the irradiance intensity on the substrate increased by 147%,while the irradiance intensity at the optical fiber receiving end improved from 0 to 1.53%,compared to the independent light source config-uration.When installed on a coating machine,the collimated focusing coupled optical system demonstrat-ed a 362.3%improvement in signal intensity and a 91.9%enhancement in the signal-to-noise ratio com-pared to the independent light source.Experimental validation involved the fabrication of narrow-band fil-ter films with a central wavelength of 365 nm and a bandwidth of 10 nm.Continuous deposition across three coating cycles achieved a central wavelength shift of less than 1 nm and a full width at half maximum of 10 nm.These results confirm that the proposed system enables high-precision monitoring of narrow-band filter films across wavelengths ranging from the near-ultraviolet to the visible and near-infrared regions.

关 键 词：光学薄膜 膜厚监控 光路设计 光纤耦合 光学膜厚 

分 类 号：O484[理学—固体物理] TB43[理学—物理]