Measuring Parallelism for Two Thin Parallel Beams Based on Autocollimation Principle

Abstract:

In order to measure the parallelism of two thin parallel beams in multi-axis interferometers and differential interferometers, the autocollimation principle was used by locating a CCD at the focal plane of collimation lens, the two beams converge on CCD image plane at different points when they are not parallel, and the distance between the two converging points is used to calculate the parallelism of the two beams. To achieve high accuracy and low system error, the CCD defocus and tilt should be strictly controlled according to the accuracy requirement. A centroid algorithm with grey threshold was used to reduce the influence of image noise. A beam-selected structure was designed to let the two beams converge to the CCD image plane in sequence to avoid superposition of beam spots. An experimental setup is built to verify the validity of the method. Experimental results show that the system has a centroid position resolution of 0.05 arcsec and a centroid position stability of 0.4 arcsec. It is therefore concluded that the method can be used to measure parallelism that is more than few arcsecs for two thin beams. Moreover, the measuring accuracy of this method can be improved when higher centroid position stability is achieved.

• Periodical: Key Engineering Materials (Volume 613)
• Pages: 157-166
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.613.157
• Online since: May 2014
• Authors: Zhen Gang Lu*, Shen Lin, Tao Zheng, Lu Yang Zhang, Jiu Bin Tan
• Keywords: Autocollimation, Beam Parallelism, Centroid Algorithm, Muti-Axis Interferometer, Thin Beam

References

[1] Zanoni C, Differential interferometer arrangements for distance and angle measurements: principles, advantages and applications, VDI-Ber, 1989, Vol. 749, pp.93-106.

[2] Hosoe, Shigeru, Laser interferometric system for displacement measurement with high precision, Nanotechnology, 1991, Vol. 2, No. 2, p.88.

DOI: 10.1088/0957-4484/2/2/002

[3] Hosoe Shigeru. Highly precise and stable displacement-measuring laser interferometer with differential optical paths, Precision Engineering, 1995, Vol. 17, No. 4, pp.258-265.

DOI: 10.1016/0141-6359(94)00022-r

[4] Lin L, Ding W X, Brower D L, et al, Differential interferometry for measurement of density fluctuations and fluctuation-induced transport(Invited), Review of Scientific Instruments, 2010, Vol. 81, No. 10, pp. 10D509.

DOI: 10.1063/1.3464480

[5] Cheol Song, Tae Joong Kim and Gweon Dae Gab, Beam scanning confocal differential heterodyne interferometry, International Journal of Optomechatronics, 2007, No. 1, p.27–45.

DOI: 10.1080/15599610701261076

[6] Lerotic, Mirna, Finding the patterns in complex specimens by improving the acquisition and analysis of x-ray spectromicroscopy data, PhD thesis, Department of Physics and Astronomy, Stony Brook University, (2005).

[7] Moosmüller, H., and W. P. Arnott, Folded Jamin interferometer: a stable instrument for refractive-index measurements, Optics Letters, 1996, Vol. 21, No. 6, pp.438-440.

DOI: 10.1364/ol.21.000438

[8] Van Der Werf, Jan E., and Peter Dirksen, Differential interferometer system and lithographic step-and-scan apparatus provided with such a system, U.S. Patent 6, 046, 792. (2000).

[9] Cunningham, M. J., S. T. Cheng, and W. W. Clegg, A differential interferometer for scanning force microscopy, Measurement Science and Technology, 1994, Vol. 5, No. 11, p.1350.

DOI: 10.1088/0957-0233/5/11/005

[10] Schwenke Heinrich, Ulrich Neuschaefer-Rube, Tilo Pfeifer, et al, Optical methods for dimensional metrology in production engineering, CIRP Annals-Manufacturing Technology, 2002, Vol. 51, No. 2, pp.685-699.

DOI: 10.1016/s0007-8506(07)61707-7

[11] Lazar, J., Hrabina, J., Šerý, M., Klapetek, P., & Číp, O. Multiaxis interferometric displacement measurement for local probe microscopy, Central European Journal of Physics, Vol. 10, No. 1, 225-231, (2012).

DOI: 10.2478/s11534-011-0093-5

[12] Lazar, J., Číp, O., Čížek, M., Hrabina, J., Šerý, M., et. al, Multiaxis interferometric system for positioning in nanometrology, Proceedings of the 9th WSEAS international conference on Microelectronics, nanoelectronics, optoelectronics, World Scientific and Engineering Academy and Society (WSEAS), 2010, pp.92-95.

DOI: 10.2478/s11534-011-0093-5

[13] Yuan, Jie, and Xingwu Long, CCD-area-based autocollimator for precision small-angle measurement, Review of Scientific Instruments, 2003, Vol. 74, No. 3, pp.1362-1365.

DOI: 10.1063/1.1539896

[14] Yuan, Jie, Xingwu Long, and Kaiyong Yang, Temperature-controlled autocollimator with ultrahigh angular measuring precision, Review of Scientific Instruments, 2005, Vol. 76, No. 12, 125106.

DOI: 10.1063/1.2149010

[15] A Just, M Krause, R Probst and R Wittekopf, Calibration of high-resolution electronic autocollimators against an angle comparator, Metrologia, 2003, Vol. 40, No. 5, p.288.

DOI: 10.1088/0026-1394/40/5/011

[16] Ralf D. Geckeler, Andreas Just, Michael Krause, Valeriy V. Yashchuk, Autocollimators for deflectometry: Current status and future progress, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2010, Vol. 616, No. 2, pp.140-146.

DOI: 10.1016/j.nima.2009.11.021

[17] Tanfer Yandayan, Bulent Ozgur, Nuray Karaboce and Orhan Yaman, High precision small angle generator for realization of the SI unit of plane angle and calibration of high precision autocollimators, Measurement Science and Technology, 2012, Vol. 23, No. 9, p.094006.

DOI: 10.1088/0957-0233/23/9/094006

[18] G Ehret, M Schulz, M Stavridis and C Elster, Deflectometric systems for absolute flatness measurements at PTB, " Measurement Science and Technology, 2012, Vol. 23, No. 9, p.094007.

DOI: 10.1088/0957-0233/23/9/094007