本研究開發一套物體厚度量測系統，應用於量測透鏡的厚度以及表面形貌等關鍵參數。本系統架構為共焦顯微鏡，相較於傳統的顯微鏡系統，兩者間的差異為共焦顯微鏡系統利用了空間針孔，濾除待測物在非焦點平面的反射光，因此在光學顯微技術當中，共焦顯微術擁有了較高的空間解析度。
在量測平行面板厚度實驗中，當塊規的表面移動到系統焦平面位置時，其表面反射光通過針孔由光偵測器所接收，透過線性移動平台的移動量可以進而得到待測物體的厚度值。藉由量測不同厚度之塊規，校正系統因為環境因素影響與機構架設所造成的誤差，從量測塊規的實驗中，驗證此系統的量測能力，量測值與塊規標稱值的差量小於3 um。為了量測透鏡中心厚度值，採用自定心夾具的機構來定位透鏡中心位置，以利透鏡厚度量測實驗。透過實驗驗證本系統的量測性能，其系統解析度為1.8 um，量測物件的厚度最大範圍約是20 mm，以及每一次量測物件厚度的時間小於10 sec。

This study presents an object thickness measurement system, applicable to measurement of lens thickness and surface topography. The configuration of this system is a confocal microscopy system. As compared to traditional microscopy system, confocal microscopy system utilizes a pinhole to filter out-of-focus light beam from non-focal plane. Therefore, in the field of optical microscopy, confocal microscopy is capable of achieving higher spatial resolution.
In the experiment of panel thickness measurement, surface of the gauge block is moved to focal plane of the system. Reflected light from gauge block is passed through a pinhole and then received by photodetector. Thickness of the sample is obtained by calculation as displacement of linear stage is a known parameter. By measuring gauge blocks of different thicknesses, the system is calibrated to compensate errors caused by environmental factors and mechanical system. Measurement capability of the system is verified through the gauge block measurement experiment. The differences between the measured values and the standard values are less than 3 um.
In order to measure central thickness of a lens, self-centering lens mount is used for alignment. Performance of the measurement system is verified through experiments. This measurement system is able to achieve resolution of 1.8 um, maximum measuring range of approximately 20 mm, and operating time of 10 sec.

[1] P. J. Duke and A. G. Michette, “Modern Microscopies,” Ch. 2, 10, 12, 1990.
[2] A. Barty, K. A. Nugent, D. Paganin and A. Roberts, “Quantitative optical phase microscopy,” Opt. Lett., 23(11), 817-819, 1998.
[3] W. H. Yeh, J. Carriere and M. Mansuripur, “Polarization microscopy of magnetic domains for magneto-optical disks,” Appl. Optics, 38(17), 3749-3758, 1999.
[4] Y. C. Hsieh and M. Mansuripur, “Image contrast in polarization microscopy of magneto-optical disk data-storage media through birefringent plastic substrates,” Appl. Optics, 36(20), 4839-4852, 1997.
[5] G. M. Holzwarth, D. B. Hill and E. B. McLaughlin, “Polarization-modulated differential-interference contrast microscopy with a variable retarder,” Appl. Optics, 39(34), 6288-6294, 2000.
[6] D. B. Murphy and M. W. Davidson, “Fundamentals of Light Microscopy and Electronic Imaging,” Ch. 10, 153-175, 2001.
[7] V. Daria, C. M. Blanca, O. Nakamura, S. Kawata and C. Saloma, “Image contrast enhancement for two-photon fluorescence microscopy in a turbid medium,” Appl. Optics, 37(34), 7960-7967, 1998.
[8] C. M. Blanca and C. Saloma, “Two-color excitation fluorescence microscopy through highly scattering media,” Appl. Optics, 40(16), 2722-2729, 2001.
[9] D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito and J. G. Fujimoto, “Optical Coherence Tomography,” Science, 254(5035), 1178-1181, 1991.
[10] M. Marvin, “Microscopy apparatus,” U.S. Patent US3013467A, 1961.
[11] J. Pawley, “Handbook of Biological Confocal Microscopy,” Ch. 1, 2, 1-37, 2012.
[12] P. Davidovits and M. D. Egger, “Scanning Laser Microscope,” Nature, 223, 831, 1969.
[13] C. H. Lee, C. L. Guo and J. Wang, “Optical measurement of the viscoelastic and biochemical responses of living cells to mechanical perturbation,” Opt. Lett., 23(4), 307-309, 1998.
[14] S. Hell and E. H. K. Stelzer, “Properties of a 4Pi confocal fluorescence microscope,” J. Opt. Soc. Am., 9(12), 2159-2166, 1992.
[15] S. Hell and E. H. K. Stelzer, “Fundamental improvement of resolution with a 4Pi-confocal fluorescence microscope using two-photon excitation,” Opt. Commun., 93(5-6), 277-282, 1992.
[16] S. W. Hell, S. Lindek, C. Cremer and E. H. K. Stelzer, “Measurement of the 4Pi‐confocal point spread function proves 75 nm axial resolution,” Appl. Phys. Lett., 64, 1335-1337, 1998.
[17] C. Sheppard and D. Shotton, “Confocal Laser Scanning Microscopy,” Ch. 5, 1997.
[18] E. H. K. Stelzer and S. Lindek, “Fundamental reduction of the observation volume in far-field light microscopy by detection orthogonal to the illumination axis: confocal theta microscopy,” Opt. Commun., 111(5-6), 536-547, 1994.
[19] T. Tanaami, S. Otsuki, N. Tomosada, Y. Kosugi, M. Shimizu and H. Ishida, “High-speed 1-frame/ms scanning confocal microscope with a microlens and Nipkow disks,” Appl. Optics, 41(22), 4704-4708, 2002.
[20] A. R. Rouse, H. Makhlouf, A. A. Tanbakuchi and A. F. Gmitro, “A multipoint scanner for high frame rate confocal microendoscopy,” Proc. SPIE, 7558, 755809-1, 2010.
[21] M. Ishihara and H. Sasaki, “High-speed surface measurement using a non-scanning multiple-beam confocal microscope,” Opt. Eng., 38(6), 1035-1040, 1999.
[22] C. H. Lee, H. Y. Mong and W. C. Lin, “Noninterferometric wide-field optical profilometry with nanometer depth resolution,” Opt. Lett., 27(20), 1773-1775, 2002.
[23] C. H. Lee and J. Wang, “Noninterferometric differential confocal microscopy with 2-nm depth resolution,” Opt. Commun., 135(4-6), 233-237, 1997.
[24] C. H. Lee and W. C. Lin, “Using differential confocal microscopy to detect the phase transition of lipid vesicle membranes,” Opt. Eng., 40(10), 2077-2083, 2001.
[25] A. Miks, J. Novak and P. Novak, “Analysis of method for measuring thickness of plane-parallel plates and lenses using chromatic confocal sensor,” Appl. Optics, 49(17), 3259-3264, 2010.
[26] Y. Tan, K. Zhu and S. Zhang, “New method for lens thickness measurement by the frequency-shifted confocal feedback,” Opt. Commun., 380, 91-94, 2016.
[27] 耿繼業、何建娃，幾何光學 第三版，全華圖書，2012。
[28] M. Born and E. Wolf, “Principles of Optics,” Ch. 7, 8, 2011.
[29] 氦氖雷射的圓孔繞射圖樣，
取自 https://commons.wikimedia.org/wiki/File:Laser_Interference.JPG
[30] 朱士維，「光學顯微技術的新進展」，台大物理系系刊，76-81，2008。
[31] T. Wilson1 and A. R. Carlini, “Size of the detector in confocal imaging systems,” Opt. Lett., 12(4), 227-229, 1987.
[32] Rayleigh criterion,
取自 http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/Raylei.html。
[33] 傳統光學顯微鏡與共焦顯微鏡所觀察的影像圖，
取自 http://abrc.sinica.edu.tw/icm/app_out/main/theorem.php
[34] Z Stack,
取自 https://cam.facilities.northwestern.edu/588-2/z-stack/
[35] 陳柏菁，「共焦顯微術系統之設計與裝置」，國立台灣大學，碩士論文，民國91年。
[36] Scanning and resolution,
取自 https://myscope.training/legacy/confocal/confocal/image/resolution.php
[37] 雷射二極體尺寸圖，
取自 https://www.thorlabs.com/drawings/e69f54a87f5e4ab6-B75C529A-F263-4939-C02B036CA0407337/CPS635R-SpecSheet.pdf
[38] 線性移動平台規格，http://www.micronixusa.com/motion/assets/docs/datasheets/PZS-90_Datasheet_v1.0_lowres.pdf