Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
권호 표지
DOI QR코드

DOI QR Code

Transparent Plate Thickness Measurement Approach Using a Chromatic Confocal Sensor Based on a Geometric Phase Lens

기하 위상 렌즈 기반의 색공초점 센서를 이용한 투명 물질 두께 측정 연구

  • Song, Min Kwan (Department of Photonic Engineering, Chosun University) ;
  • Park, Hyo Mi (Department of Photonic Engineering, Chosun University) ;
  • Joo, Ki-Nam (Department of Photonic Engineering, Chosun University)
  • 송민관 (조선대학교 광기술공학과) ;
  • 박효미 (조선대학교 광기술공학과) ;
  • 주기남 (조선대학교 광기술공학과)
  • Received : 2022.10.12
  • Accepted : 2022.11.28
  • Published : 2022.12.25
Download PDF
⟨ Previous Next ⟩

Abstract

In this investigation, we describe a chromatic confocal sensor based on a geometric phase lens for measuring the thicknesses of transparent plates. In order to design a compact sensor, a geometric phase lens, which has diffractive and polarizing characteristics, is used as a device to generate chromatic aberration, and a fiber optic module is adopted. The systematic error of the sensor is reduced with wavelength peak detection by Gaussian curve fitting and the common error compensation obtained by the repeatedly consecutive experimental results. An approach to calculate the plate thickness is derived and verified with sapphire and BK7 plates. Because of the simple and compact design of the proposed sensor with rapid measurement capability, it is expected to be widely used in thickness measurements of transparent plates as an alternative to traditional approaches.

본 논문에서는 투명한 물질의 두께를 측정하기 위한 방법으로 기하 위상 렌즈 기반의 색공초점 센서를 개발하고, 성능 개선을 위한 보정 방법을 제시한다. 일반적인 색공초점 센서의 복잡한 설계로 인한 한계를 극복하기 위해, 기하 위상 렌즈를 이용하여 전체 시스템의 크기를 줄이고, 시스템 오차를 보상하기 위한 파장 첨두 위치 추출 방법과 계통 오차 제거 방법을 설명한다. 색공초점 센서를 이용하여 투명한 물질의 두께를 측정하기 위한 이론을 설명하고, 이를 사파이어 및 BK7 물질의 두께를 측정함으로써 실험적으로 검증한다. 색공초점 센서를 이용한 두께 측정 방법은 기존의 간섭계 및 공초점 센서의 방법들에 비해 측정 속도가 빠르고, 분산 등에 의한 두께 측정 영역 제한이 없기 때문에 많은 응용이 가능하다.

Keywords

References

  1. P. A. Flournoy, R. W. McClure, and G. Wyntjes, "White-light interferometric thickness gauge," Appl. Opt. 11, 1907-1915 (1972). https://doi.org/10.1364/AO.11.001907
  2. W. V. Sorin and D. F. Gray, "Simultaneous thickness and group index measurement using optical low-coherence reflectometry," IEEE Photonics Technol. Lett. 4, 105-107 (1992). https://doi.org/10.1109/68.124892
  3. T. Fukano and I. Yamaguchi, "Separation of measurement of the refractive index and the geometrical thickness by use of a wavelength-scanning interferometer with a confocal microscope," Appl. Opt. 38, 4065-4073 (1999). https://doi.org/10.1364/AO.38.004065
  4. C. Saloma, K. Matsuoka, and S. Kawata, "Optical thickness profiling using a semiconductor laser confocal microscope," Rev. Sci. Instrum. 67, 2072-2078 (1996). https://doi.org/10.1063/1.1147017
  5. L. Deck and P. De Groot, "High-speed noncontact profiler based on scanning white-light interferometry," Appl. Opt. 33, 7334-7338 (1994). https://doi.org/10.1364/AO.33.007334
  6. U. Schnell, E. Zimmermann, and R. Dandliker, "Absolute distance measurement with synchronously sampled white-light channelled spectrum interferometry," Pure Appl. Opt. 4, 643-651 (1995). https://doi.org/10.1088/0963-9659/4/5/016
  7. Y. H. Yun, Y. B. Seo, and K.-N. Joo, "Elimination of the direction ambiguity and the dead zone in spectrally resolved interferometry," Meas. Sci. Technol. 27, 035004 (2016). https://doi.org/10.1088/0957-0233/27/3/035004
  8. H. J. Tiziani, M. Wegner, and D. Steudle, "Confocal principle for macro-and microscopic surface and defect analysis," Opt. Eng. 39, 32-39 (2000). https://doi.org/10.1117/1.602332
  9. I. K. Ilev, R. W. Waynant, K. R. Byrnes, and J. J. Anders, "Dual-confocal fiber-optic method for absolute measurement of refractive index and thickness of optically transparent media," Opt. Lett. 27, 1693-1695 (2002). https://doi.org/10.1364/OL.27.001693
  10. S. Kim, J. Na, M. J. Kim, and B. H. Lee, "Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics," Opt. Express 16, 5516-5526 (2008). https://doi.org/10.1364/OE.16.005516
  11. H. J. Tiziani and H.-M. Uhde, "Three-dimensional image sensing by chromatic confocal microscopy," Appl. Opt. 33, 1838-1843 (1994). https://doi.org/10.1364/AO.33.001838
  12. A. Miks, J. Novak, and P. Novak, "Analysis of method for measuring thickness of plane-parallel plates and lenses using chromatic confocal sensor," Appl. Opt. 49, 3259-3264 (2010). https://doi.org/10.1364/AO.49.003259
  13. M. Hillenbrand, B. Mitschunas, C. Wenzel, A. Grewe, X. Ma, P. Fesser, M. Bichra, and S. Sinzinger, "Hybrid hyperchromats for chromatic confocal sensor systems," Adv. Opt. Technol. 1, 187-194 (2012). https://doi.org/10.1515/aot-2012-0017
  14. H. M. Park, U. Kwon, and K.-N. Joo, "Vision chromatic confocal sensor based on a geometrical phase lens," Appl. Opt. 60, 2898-2901 (2021). https://doi.org/10.1364/AO.423339
  15. L. A. Aleman-Castaneda, B. Piccirillo, E. Santamato, L. Marrucci, and M. A. Alonso, "Shearing interferometry via geometric phase," Optica 6, 396-399 (2019). https://doi.org/10.1364/optica.6.000396
  16. D. Luo, C. Kuang, and X. Liu, "Fiber-based chromatic confocal microscope with Gaussian fitting method," Opt. Laser Technol. 44, 788-793 (2012). https://doi.org/10.1016/j.optlastec.2011.10.027