摘要
为满足GREGOR望远系统末端的测试需求,实现对某些荧光光谱干扰信号的有效过滤和屏蔽,在可见光范围内设计并制备了一种高透射深截止多腔负滤光片。采用变迹函数不同级次的高阶迭代算法,通过设计厚度调制层来有效抑制通带波纹;在B270基底上采用离子束辅助反应磁控溅射的沉积方法进行制备,使用光控法和时间控制法相结合的方案对非四分之一膜层厚度进行监控。实验结果表明,实际制备结果与理论设计吻合较好,制备工艺可行性较高。所设计的多腔负滤光片膜系结构总层数为190层,总厚度约为20μm,测得各通带透射率均大于90%,截止深度大于0.1%,反射带半峰全宽小于24 nm,最大位置偏差为2 nm,样品的均匀性良好,测试结果完全满足实际应用需求。
Objective GREGOR is an assembled solar telescope with 1.5 m diameter that is designed for high-precision measurements of the magnetic field and gas motion in the solar photosphere and chromosphere with a resolution of 70 km on the sun and high-resolution stellar spectroscopy.To meet the specific requirements of measurement using the GREGOR telescope system,the surfaces of the lenses need to be modified using interference coatings.These coatings form the optical filters required to achieve the rejection bands at the specific wavelength ranges originating from fluorescence.Therefore,a multi-notch filter covering visible light with high transmittance for passbands and high optical density for rejection bands is designed and fabricated to improve the signal-to-noise ratio,where the noise signals are rejected.Methods In this design,two materials with high and low refractive indices are employed and the ripples in the passband regions are suppressed by modulating the layer thicknesses of the layer stacks with high order apodization functions.As the full width at half maximum(FWHM) and central wavelength of the multi-rejection bands are also specified,high-order iteration algorithms are used to insert and adjust modulating layers to achieve the desired merit functions.This realizes the global search for a multi-band notch filter with effective ripple suppression.The designed multi-notch filters are then fabricated on B270 substrates using ion-beam-assisted reactive magnetron sputtering deposition.Optical monitoring and time control methods are used to control the thickness of the nonquarter wavelength optical thickness(QWOT) layers.The trigger point of the deposition of each layer can be determined using the turning points of the QWOT if the thicknesses are larger than the QWOT,whereas the trigger point of the deposition of each layer is determined by time using the average deposition rate for thicknesses less than the QWOT.The errors in the layer thickness can be automatically compensated by the optical monitoring meth
作者
常艳贺
付秀华
张功
张静
李春
Shigeng Song
Chang Yanhe;Fu Xiuhua;Zhang Gong;Zhang Jing;Li Chun;Shigeng Song(School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;Zhongshan Institute,Changchun University of Science and Technology,Zhongshan 528437,Guangdong,China;State Key Laboratory of Applied Optics,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China;Institute of Thin Films,Sensors and Imaging,School of Engineering and Computing,University of the West of Scotland,PaisleyPAl2BE,UK)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2023年第13期36-43,共8页
Chinese Journal of Lasers
基金
高等学校学科创新引智计划(111计划D21009)。
