Research on Diopter Measurement Based on Extended Broadband optical Double Grating Interference
LI Tian-hao1,2,HE Yong1,2,HAN Zhi-gang2,XÜ Hai-fei1
1. School of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
2. Key Laboratory of Advanced Solid Laser Industry and Information Technology Ministry, Nanjing University of Science and Technology,Nanjing, Jiangsu 210094, China
Abstract：A diopter measurement based on the double grating system with extended broadband light is proposed. Based on Talbot effection and Moire effection, the intensity distribution formula of interference under extended monochromatic light and extended polychromatic light is derived. As it shows that if the distance from the light to the first grating and the distance from the second grating to the screen is equal, the intensity distribution of the interference won’t be related to the wavelength of the light. Besides the influence of double grating system parameters on the contrast of Moire fringe under extended light is analyzed. The results show that when the width of light is 4mm, the grating period is 0.2mm, the angle between two gratings is 1.9°, and the space distance between two gratings is 6.5mm, the clear interference fringe can be obtained. A diopter measurement system is constructed to measure the lens with diopter of -1m-1, -3m-1, 1m-1 and 3m-1. The peak-to-valley deviation of measurements is 0.0064m-1, which is the 0.28% of the average measurement results. The experiment result shows that the lens diopter can be measured with double grating system using extended broadband light source accurately and cheaply.
Liu Q. Talbot effect of extended light source illumination without collimating lens［J］. Journal of Inner Mongolia Institute of technology, 1990(1): 50-56.
Ding Y, Luo H Y, Shi H L, et al. Research on adaptive fringe template of spatiotemporal joint modulation spatial heterodyne interferometric imager［J］.Acta optica Sinica, 2022, 42(1): 273-283
［6］
于雪. 基于泰伯莫尔效应的滚转角检测方法的研究［D］. 天津: 天津大学, 2015.
Lü W S. Measuring micro angular displacement with Moire fringe［J］. Optical Engineering, 1978(3): 44-48.
Zhang J Y, Liu W L, Gao M L. Research on metrological calibration and traceability of human corneal parameters［J］. Acta Metrology Sinica, 2020, 41(11): 1339-1343.
［4］
Nakano Y. Measurements of the small tilt-angle variation of an object surface using moire interferometry and digital image processing［J］. Applied Optics, 1987, 26(18): 3911-3914.
Tian X Q, Kong L F, Kong D M. Using discrete stationary wavelet transform to improve NURBS quadric surface fitting method［J］. Acta Metrology Sinica, 2020, 41(6): 662-668.
［14］
Jia L, Jian B, Jin Z. Long focal-length measurement using divergent beam and two gratings of different periods［J］. Optics Express, 2014, 22(23): 27921-27931.
［15］
陆衡. 基于泰伯效应的长焦距测量系统的设计［D］. 南京: 南京理工大学, 2014.
Xu H F, He Y. Research on diopter measurement technology of progressive multifocal lens based on phase-shifting Taber interferometer［J］. Progress in laser and Optoelectronics: 2022, 59(13): 253-258.
［18］
Chen H, He Y, Li J, et al. Measurement of long focal lengths with a double-grating interferometer［J］. Applied Optics, 2013, 52(27): 6696-6702.
［5］
Kim B J , Song J S. Determination of small angular displacement by moiré fringes of matched radial-parallel grating［J］. Applied Optica, 1997, 36(13): 2848-2855.
［7］
吕文松. 用莫尔条纹测量微小角位移［J］. 光学工程, 1978(3): 44-48.
［12］
陈好. 数字图像处理技术在长焦距测量系统中的应用研究［D］. 南京: 南京理工大学, 2014.
Hai B, Zhang H L. Using Young's interference model to explain the achromatic effect of white light double grating［J］. Optical instruments, 1994, 16(1): 4-6
Jiang Z D, Chen L, He Y. Research on focal length measurement technology based on double Lange grating［J］. Applied Optics, 2018, 39(5): 687-690.
2023, Vol. 44 
