Research on a Multi-Channel Chromatic Confocal Imaging System

doi:10.3969/j.issn.1007-5461.2026.03.005

Abstract

Abstract: To address the limitations of slow scanning speed and high system complexity in traditional point-scanning chromatic confocal three-dimensional imaging technology, a multi-point synchronous imaging system based on fiber array and galvanometer-based optical switching mechanism is proposed. The system employs a 32-channel one-dimensional fiber array as the detection core, combined with a high-numerical-aperture dispersive lens and a high-speed galvanometer, to achieve rapid multi-point data acquisition and high-precision topographic reconstruction. Furthermore, a peak-search algorithm is proposed to effectively enhance the accuracy of wavelength determination of the system. The calibration results demonstrate that the system has a longitudinal accuracy of 0.14 µm at 580 nm and 2.46 µm across the working spectral range of 450–700 nm. Based on this, the system has been successfully applied to the inspection of integrated circuit micro-topography. This system significantly improves measurement efficiency while maintaining high resolution, showing strong potential for industrial online applications.

Key words: chromatic confocal measurement, three-dimensional topography detection, fiber array, optical fiber switching

CLC Number:

O431.2

IKEDA Kiichi , , ZANG Haofeng , LU Yonghua , , WANG Pei , . Research on a Multi-Channel Chromatic Confocal Imaging System[J]. Chinese Journal of Quantum Electronics, 2026, 43(3): 375-383.

References

[1] Blais F. Review of 20 years of range sensor development [J]. Journal of Electronic Imaging, 2004, 13(1): 231-244.
[2] Sansoni G, Trebeschi M, Docchio F. State-of-the-art and applications of 3D imaging sensors in industry [J], cultural heritage, medicine, and criminal investigation. Sensors, 2009, 9(1): 568-601.
[3] Berkovic G, Shafir E. Optical methods for distance and displacement measurements [J]. Advances in Optics and Photonics, 2012, 4(4): 441-472.
[4] Zou X, Zhao X, Li G, Li Z, Sun T. Non-contact on-machine measurement using a chromatic confocal probe for an ultra-precision turning machine [J]. International Journal of Advanced Manufacturing Technology, 2017, 90(5): 2163-2172.
[5] Liu C, Wang Y, Zhao W, Zhu L. High-resolution divided-aperture differential confocal sensing technique [J]. Chinese Journal of Scientific Instrument, 2017, 38(9): 2225-2231.
刘超, 王允, 赵维谦, 祝连庆. 高分辨力分光瞳差动共聚焦传感技术研究[J]. 仪器仪表学报, 2017, 38(9): 2225-2231.
[6] Browne M A, Akinyemi O, Crossley F, Stacey D T B. Stage-scanned chromatically aberrant confocal microscope for 3-D surface imaging [C]. Biomedical Image Processing and Three-Dimensional Microscopy: Vol. 1660. SPIE, 1992: 532-541.
[7] ZOU J wu, YU Q, CHENG F. Differential chromatic confocal roughness evaluation system and experimental research [J]. Chinese Optics [J], 2020, 13(5): 1103-1114.
邹景武, 余卿, 程方. 差动式彩色共聚焦粗糙度评定系统及实验研究[J]. 中国光学, 2020, 13(5): 1103-1114.
[8] Du H L, Zhang W H, Ju B F, Sun Z, Sun A. A new method for detecting surface defects on curved reflective optics using normalized reflectivity [J]. Review of Scientific Instruments, 2020, 91(3).
[9] Weng C J, Lu B R, Cheng P Y, Hwang C H, Chen C Y. Measuring the thickness of transparent objects using a confocal displacement sensor [C]. IEEE INTERNATIONAL INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE (I2MTC). Politecnico Torino, Torino, ITALY: IEEE, 2017: 1531-1535.
[10] Li J, Zhao Y, Du H, Zhu X, Wang K, Zhao M. Adapative modal decomposition based overlapping-peaks extraction for the thickness measurement in chromatic confocal microscopy [J]. Optics Express, 2020, 28(24): 36176-36187.
[11] Levoy M, Pulli K, Curless B, Rusinkiewicz S, Koller D, Pereira L, Ginzton M, Anderson S, Davis J, Ginsberg J, Shade J, Fulk D. The digital michelangelo project: 3D scanning of large statues [C].SIGGRAPH 2000 CONFERENCE PROCEEDINGS. New Orleans, La: Assoc Computing Machinery, 2000: 131-144.
[12] Javier Brosed F, Jose Aguilar J, Guillomia D, Santolaria J. 3D geometrical inspection of complex geometry parts using a novel laser triangulation sensor and a robot [J]. Sensors, 2011, 11(1): 90-110.
[13] Ito S, Poik M, Csencsics E, Schlarp J, Schitter G. High-speed scanning chromatic confocal sensor for 3-D imaging with modeling-free learning control [J]. Applied Optics, 2020, 59(29): 9234.
[14] Wertjanz D, Kern T, Csencsics E, Stadler G, Schitter G. Compact scanning confocal chromatic sensor enabling precision 3-D measurements [J]. Applied Optics, 2021, 60(25): 7511-7517.
[15] Chun B S, Kim K, Gweon D. Three-dimensional surface profile measurement using a beam scanning chromatic confocal microscope [J]. Review of Scientific Instruments, 2009, 80(7): 73706.
[16] Csencsics E, Ito S, Schlarp J, Schitter G. System integration and control for 3D scanning laser metrology [J]. IEEJ Journal of Industry Applications, 2019, 8(2): 207-217.
[17] WANG J, LIU T, TANG X, HU J, WANG X, LI G, HE T, YANG S. Fiber-coupled Chromatic Confocal 3D Measurement System and Comparative Study of Spectral Data Processing Algorithms [J]. Acta Photonica Sinica, 2021, 50(11): 131-144.
王佳怡, 刘涛, 唐晓锋, 胡佳琪, 王兴, 李国卿, 何韬, 杨树明. 光纤式色散共焦三维测量系统及算法比较研究[J]. 光子学报, 2021, 50(11): 131-144.
[18] Fuerst M E, Csencsics E, Haider C, Schitter G. Confocal chromatic sensor with an actively tilted lens for 3D measurement [J]. Journal of the Optical Society of America A, 2020, 37(9): B46.
[19] Zhang Y, Yu Q, Cheng F, Wang Y, Wang C. Fiber Bundle-based Parallel Chromatic Confocal Measurement System and Experimental Study [J]. Chinese Journal of Scientific Instrument, 2020, 41(12): 23-31.
张雅丽, 余卿, 程方, 王寅, 王翀. 光纤束并行彩色共聚焦测量系统及实验研究[J]. 仪器仪表学报, 2020, 41(12): 23-31.