Calibration and optimization of an x-ray bendable mirror using displacement-measuring sensors

Maurizio Vannoni; Idoia Freijo Martín; Valerija Music; Harald Sinn

doi:10.1364/OE.24.017292

Calibration and optimization of an x-ray bendable mirror using displacement-measuring sensors

Maurizio Vannoni, Idoia Freijo Martín, Valerija Music, and Harald Sinn

Optics Express
Vol. 24,
Issue 15,
pp. 17292-17302
(2016)
•https://doi.org/10.1364/OE.24.017292

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Maurizio Vannoni, Idoia Freijo Martín, Valerija Music, and Harald Sinn, "Calibration and optimization of an x-ray bendable mirror using displacement-measuring sensors," Opt. Express 24, 17292-17302 (2016)

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Related Topics
Table of Contents Category
- Instrumentation, Measurement, and Metrology
Optics & Photonics Topics
?

The topics in this list come from the OSA Optics and Photonics Topics applied to this article.
Previously assigned OCIS codes
- Instrumentation, measurement, and metrology (120.0120)
- Metrology (120.3940)
- Remote sensing and sensors (280.0280)
- X-ray mirrors (340.7470)

About this Article
History
- Original Manuscript: May 5, 2016
- Revised Manuscript: June 22, 2016
- Manuscript Accepted: June 24, 2016
- Published: July 21, 2016

Accessible

Open Access

Abstract

We propose a method to control and to adjust in a closed-loop a bendable x-ray mirror using displacement-measuring devices. For this purpose, the usage of capacitive and interferometric sensors is investigated and compared. We installed the sensors in a bender setup and used them to continuously measure the position and shape of the mirror in the lab. The sensors are vacuum-compatible such that the same concept can also be applied in final conditions. The measurement is used to keep the calibration of the system and to create a closed-loop control compensating for external influences: in a demonstration measurement, using a 950 mm long bendable mirror, the mirror sagitta is kept stable inside a range of 10 nm Peak-To-Valley (P-V).

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References

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Publication

M. Altarelli, R. Brinkmann, M. Chergui, W. Decking, B. Dobson, S. Düsterer, G. Grübel, W. Graeff, H. Graafsma, J. Hajdu, J. Marangos, J. Pflüger, H. Redlin, D. Riley, I. Robinson, J. Rossbach, A. Schwarz, K. Tiedtke, T. Tschentscher, I. Vartaniants, H. Wabnitz, H. Weise, R. Wichmann, K. Witte, A. Wolf, M. Wulff, and M. Yurkov, eds., “The European X-ray Free-Electron Laser,” Technical Design Report, DESY 2006–097 (2007).
M. Weiser, “Ion beam figuring for lithography optics,” Nucl. Instrum. Methods Phys. Res. B 267(8-9), 1390–1393 (2009).
[Crossref]
J. Arkwright, J. Burke, and M. Gross, “A deterministic optical figure correction technique that preserves precision-polished surface quality,” Opt. Express 16(18), 13901–13907 (2008).
[Crossref] [PubMed]
T. Arnold, G. Böhm, R. Fechner, J. Meister, A. Nickel, F. Frost, T. Hänsel, and A. Schindler, “Ultra-precision surface finishing by ion beam and plasma jet techniques—status and outlook,” Nucl. Instrum. Meth. A 616(2-3), 147–156 (2010).
[Crossref]
Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]
M. Vannoni and G. Molesini, “Validation of absolute planarity reference plates with a liquid mirror,” Metrologia 42(5), 389–393 (2005).
[Crossref]
M. Vannoni, “Absolute flatness measurement using oblique incidence setup and an iterative algorithm. A demonstration on synthetic data,” Opt. Express 22(3), 3538–3546 (2014).
[Crossref] [PubMed]
F. Siewert, J. Buchheim, S. Boutet, G. J. Williams, P. A. Montanez, J. Krzywinski, and R. Signorato, “Ultra-precise characterization of LCLS hard X-ray focusing mirrors by high resolution slope measuring deflectometry,” Opt. Express 20(4), 4525–4536 (2012).
[Crossref] [PubMed]
M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]
R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]
L. A. Poyneer, T. McCarville, T. Pardini, D. Palmer, A. Brooks, M. J. Pivovaroff, and B. Macintosh, “Sub-nanometer flattening of 45 cm long, 45 actuator x-ray deformable mirror,” Appl. Opt. 53(16), 3404–3414 (2014).
[Crossref] [PubMed]
M. Vannoni, I. Freijo Martín, F. Siewert, R. Signorato, F. Yang, and H. Sinn, “Characterization of a piezo bendable X-ray mirror,” J. Synchrotron Radiat. 23(1), 169–175 (2016).
[Crossref] [PubMed]
T. Kimura, S. Handa, H. Mimura, H. Yumoto, D. Yamakawa, S. Matsuyama, K. Inagaki, Y. Sano, K. Tamasaku, Y. Nishino, M. Yabashi, T. Ishikawa, and K. Yamauchi, “Wavefront Control System for Phase Compensation in Hard X-ray Optics,” Jpn. J. Appl. Phys. 48(7), 072503 (2009).
[Crossref]
K. Yamauchi, H. Mimura, T. Kimura, H. Yumoto, S. Handa, S. Matsuyama, K. Arima, Y. Sano, K. Yamamura, K. Inagaki, H. Nakamori, J. Kim, K. Tamasaku, Y. Nishino, M. Yabashi, and T. Ishikawa, “Single-nanometer focusing of hard x-rays by Kirkpatrick-Baez mirrors,” J. Phys. Condens. Matter 23(39), 394206 (2011).
[Crossref] [PubMed]
V. V. Yashchuk, G. Y. Morrison, M. A. Marcus, E. E. Domning, D. J. Merthe, F. Salmassi, and B. V. Smith, “Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2,” J. Synchrotron Radiat. 22(3), 666–674 (2015).
[Crossref] [PubMed]
M. Vannoni and I. Freijo Martín, “Absolute interferometric characterization of an x-ray mirror surface profile,” Metrologia 53(1), 1–6 (2016).
[Crossref]
V. Music, “Optimisation and characterisation of a mechanical bender for X-ray mirrors,” Bachelor Thesis (University of Hamburg, 2015).
M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).
M. A. Green, “Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients,” Sol. Energy Mater. Sol. Cells 92(11), 1305–1310 (2008).
[Crossref]
B. C. Heisen, D. Boukhelef, S. Esenov, S. Hauf, I. Kozlova, L. Maia, A. Parenti, J. Szuba, K. Weger, K. Wrona, and C. Youngman, “Karabo: an Integrated Software Framework Combining Control, Data Management, and Scientific Computing Tasks,” ICALEPCS2013, San Francisco, CA, USA (2013)

2016 (3)

M. Vannoni, I. Freijo Martín, F. Siewert, R. Signorato, F. Yang, and H. Sinn, “Characterization of a piezo bendable X-ray mirror,” J. Synchrotron Radiat. 23(1), 169–175 (2016).
[Crossref] [PubMed]

M. Vannoni and I. Freijo Martín, “Absolute interferometric characterization of an x-ray mirror surface profile,” Metrologia 53(1), 1–6 (2016).
[Crossref]

M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).

2015 (1)

V. V. Yashchuk, G. Y. Morrison, M. A. Marcus, E. E. Domning, D. J. Merthe, F. Salmassi, and B. V. Smith, “Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2,” J. Synchrotron Radiat. 22(3), 666–674 (2015).
[Crossref] [PubMed]

2014 (2)

M. Vannoni, “Absolute flatness measurement using oblique incidence setup and an iterative algorithm. A demonstration on synthetic data,” Opt. Express 22(3), 3538–3546 (2014).
[Crossref] [PubMed]

L. A. Poyneer, T. McCarville, T. Pardini, D. Palmer, A. Brooks, M. J. Pivovaroff, and B. Macintosh, “Sub-nanometer flattening of 45 cm long, 45 actuator x-ray deformable mirror,” Appl. Opt. 53(16), 3404–3414 (2014).
[Crossref] [PubMed]

2012 (1)

F. Siewert, J. Buchheim, S. Boutet, G. J. Williams, P. A. Montanez, J. Krzywinski, and R. Signorato, “Ultra-precise characterization of LCLS hard X-ray focusing mirrors by high resolution slope measuring deflectometry,” Opt. Express 20(4), 4525–4536 (2012).
[Crossref] [PubMed]

2011 (1)

K. Yamauchi, H. Mimura, T. Kimura, H. Yumoto, S. Handa, S. Matsuyama, K. Arima, Y. Sano, K. Yamamura, K. Inagaki, H. Nakamori, J. Kim, K. Tamasaku, Y. Nishino, M. Yabashi, and T. Ishikawa, “Single-nanometer focusing of hard x-rays by Kirkpatrick-Baez mirrors,” J. Phys. Condens. Matter 23(39), 394206 (2011).
[Crossref] [PubMed]

2010 (3)

T. Arnold, G. Böhm, R. Fechner, J. Meister, A. Nickel, F. Frost, T. Hänsel, and A. Schindler, “Ultra-precision surface finishing by ion beam and plasma jet techniques—status and outlook,” Nucl. Instrum. Meth. A 616(2-3), 147–156 (2010).
[Crossref]

M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

2009 (2)

M. Weiser, “Ion beam figuring for lithography optics,” Nucl. Instrum. Methods Phys. Res. B 267(8-9), 1390–1393 (2009).
[Crossref]

T. Kimura, S. Handa, H. Mimura, H. Yumoto, D. Yamakawa, S. Matsuyama, K. Inagaki, Y. Sano, K. Tamasaku, Y. Nishino, M. Yabashi, T. Ishikawa, and K. Yamauchi, “Wavefront Control System for Phase Compensation in Hard X-ray Optics,” Jpn. J. Appl. Phys. 48(7), 072503 (2009).
[Crossref]

2008 (2)

J. Arkwright, J. Burke, and M. Gross, “A deterministic optical figure correction technique that preserves precision-polished surface quality,” Opt. Express 16(18), 13901–13907 (2008).
[Crossref] [PubMed]

M. A. Green, “Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients,” Sol. Energy Mater. Sol. Cells 92(11), 1305–1310 (2008).
[Crossref]

2005 (1)

M. Vannoni and G. Molesini, “Validation of absolute planarity reference plates with a liquid mirror,” Metrologia 42(5), 389–393 (2005).
[Crossref]

1987 (1)

Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]

Arima, K.

Arkwright, J.

Arnold, T.

Biasi, R.

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Böhm, G.

Boutet, S.

Brooks, A.

Buchheim, J.

Burke, J.

Domning, E. E.

Endo, K.

Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]

Fechner, R.

Freijo Martín, I.

M. Vannoni and I. Freijo Martín, “Absolute interferometric characterization of an x-ray mirror surface profile,” Metrologia 53(1), 1–6 (2016).
[Crossref]

M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).

Frost, F.

Gallieni, D.

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Green, M. A.

M. A. Green, “Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients,” Sol. Energy Mater. Sol. Cells 92(11), 1305–1310 (2008).
[Crossref]

Gross, M.

Handa, S.

Hänsel, T.

Inagaki, K.

Ishikawa, T.

Kim, J.

Kimura, T.

Krzywinski, J.

Macintosh, B.

Mantegazza, P.

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Marcus, M. A.

Matsuyama, S.

McCarville, T.

Meister, J.

Merthe, D. J.

Mimura, H.

Molesini, G.

M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]

M. Vannoni and G. Molesini, “Validation of absolute planarity reference plates with a liquid mirror,” Metrologia 42(5), 389–393 (2005).
[Crossref]

Montanez, P. A.

Mori, Y.

Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]

Morrison, G. Y.

Nakamori, H.

Nickel, A.

Nishino, Y.

Palmer, D.

Pardini, T.

Pivovaroff, M. J.

Poyneer, L. A.

Riccardi, A.

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Salinari, P.

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Salmassi, F.

Sano, Y.

Schindler, A.

Siewert, F.

Signorato, R.

Sinn, H.

M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).

Smith, B. V.

Sordini, A.

M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]

Tamasaku, K.

Vannoni, M.

M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).

M. Vannoni and I. Freijo Martín, “Absolute interferometric characterization of an x-ray mirror surface profile,” Metrologia 53(1), 1–6 (2016).
[Crossref]

M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]

M. Vannoni and G. Molesini, “Validation of absolute planarity reference plates with a liquid mirror,” Metrologia 42(5), 389–393 (2005).
[Crossref]

Weiser, M.

M. Weiser, “Ion beam figuring for lithography optics,” Nucl. Instrum. Methods Phys. Res. B 267(8-9), 1390–1393 (2009).
[Crossref]

Williams, G. J.

Yabashi, M.

Yamakawa, D.

Yamamura, K.

Yamauchi, K.

Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]

Yang, F.

Yashchuk, V. V.

Yumoto, H.

Appl. Opt. (1)

J. Phys. Condens. Matter (1)

J. Synchrotron Rad. (1)

M. Vannoni, I. Freijo Martín, and H. Sinn, “Characterization of an X-ray mirror mechanical bender for the European XFEL,” J. Synchrotron Rad. 23, 5828 (2016).

J. Synchrotron Radiat. (2)

Jpn. J. Appl. Phys. (1)

Metrologia (2)

M. Vannoni and I. Freijo Martín, “Absolute interferometric characterization of an x-ray mirror surface profile,” Metrologia 53(1), 1–6 (2016).
[Crossref]

M. Vannoni and G. Molesini, “Validation of absolute planarity reference plates with a liquid mirror,” Metrologia 42(5), 389–393 (2005).
[Crossref]

Nucl. Instrum. Meth. A (1)

Nucl. Instrum. Methods Phys. Res. B (1)

M. Weiser, “Ion beam figuring for lithography optics,” Nucl. Instrum. Methods Phys. Res. B 267(8-9), 1390–1393 (2009).
[Crossref]

Opt. Express (4)

M. Vannoni, A. Sordini, and G. Molesini, “Long-term deformation at room temperature observed in fused silica,” Opt. Express 18(5), 5114–5123 (2010).
[Crossref] [PubMed]

Precis. Eng. (1)

Y. Mori, K. Yamauchi, and K. Endo, “Elastic emission machining,” Precis. Eng. 9(3), 123–128 (1987).
[Crossref]

Proc. SPIE (1)

R. Biasi, D. Gallieni, P. Salinari, A. Riccardi, and P. Mantegazza, “Contactless thin adaptive mirror technology: past, present, and future,” Proc. SPIE 7736, 77362B (2010).
[Crossref]

Sol. Energy Mater. Sol. Cells (1)

M. A. Green, “Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients,” Sol. Energy Mater. Sol. Cells 92(11), 1305–1310 (2008).
[Crossref]

Other (3)

B. C. Heisen, D. Boukhelef, S. Esenov, S. Hauf, I. Kozlova, L. Maia, A. Parenti, J. Szuba, K. Weger, K. Wrona, and C. Youngman, “Karabo: an Integrated Software Framework Combining Control, Data Management, and Scientific Computing Tasks,” ICALEPCS2013, San Francisco, CA, USA (2013)

M. Altarelli, R. Brinkmann, M. Chergui, W. Decking, B. Dobson, S. Düsterer, G. Grübel, W. Graeff, H. Graafsma, J. Hajdu, J. Marangos, J. Pflüger, H. Redlin, D. Riley, I. Robinson, J. Rossbach, A. Schwarz, K. Tiedtke, T. Tschentscher, I. Vartaniants, H. Wabnitz, H. Weise, R. Wichmann, K. Witte, A. Wolf, M. Wulff, and M. Yurkov, eds., “The European X-ray Free-Electron Laser,” Technical Design Report, DESY 2006–097 (2007).

V. Music, “Optimisation and characterisation of a mechanical bender for X-ray mirrors,” Bachelor Thesis (University of Hamburg, 2015).

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Fig. 1 Schematic of the bender. The spring is compressed and identical reaction forces are transmitted to the levers. The mirror clamps are torqued and the mirror-reflecting surface is bent (details about the actuator mechanism are removed due to property rights).

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Fig. 2 Measurement setup to perform a calibration of the mechanical bender (top view). The Fizeau interferometer is used in an angled setup to measure the bendable mirror surface and its radius of curvature. The three displacement-measuring sensors are installed on the back of the mirror, one corresponding to the center and the other two on opposite sides.

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Fig. 3 Direct output of the capacitive sensors during a typical measurement.

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Fig. 4 Calibration curve of the bendable mirror, obtained by the Fizeau interferometer and the three capacitive sensors, without any additional correction. The two curves differ by an offset and a proportional factor.

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Fig. 5 Calibration curve of the bendable mirror, obtained by the Fizeau interferometer and the three interferometric optical sensors. In the latter case, we still have an offset, but the proportional factor is almost absent.

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Fig. 6 Short-term measurement of the sagitta for the capacitive sensors.

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Fig. 7 Short-term measurement of the sagitta for the optical sensors.

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Fig. 8 Example of a long-term measurement, with the Fizeau interferometer and the capacitive sensors measuring the mirror sagitta simultaneously. At a specified moment, the closed-loop operation mode with feedback to the capacitive sensors is activated and the sagitta is kept fixed inside the 10 nm range.

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Tables (3)

Table 1 Fizeau Interferometer Specifications

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Table 2 Capacitive Sensors Specifications

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Table 3 Optical Sensors Specifications

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Equations (2)

Equations on this page are rendered with MathJax. Learn more.

s = \frac{L^{2}}{8 R} .

R = \frac{d^{2}}{8 [(y_{1} + y_{3}) / 2 - y_{2}]},

Manufacturer, distributor	Zygo, AMETEK Germany GmbH
Model	4-inch Dynafiz plus 12-inch expander
Measuring principle	Phase-shift interferometry
Aperture diameter	304.8 mm
Source	Stabilized He–Ne laser, wavelength 632.8 nm
Repeatability	Repeatability <0.25 nm (2 σ)
Resolution	λ/12000 (high-resolution mode, double pass)
Image size	1200 x 1200 pixels
Digitization	10 bits
Flats quality (calibrated)	12 nm and 18 nm (P–V)
Flats material	Fused silica

TypeBrand	D-510.051Physik Instrumente	CSH1-CAm1.4Micro-Epsilon	CSH05-CAm1.4Micro-Epsilon
Nominal measurement range	50 μm	1000 μm	500 μm
Gap (min.-max.)	25–375 μm	0–1000 μm	0–500 μm
Static resolutionDynamic resolution	(10 Hz) 0.5 nm(10 KHz) 1 nm	(2 Hz) 0.75 nm(8.5 KHz) 20 nm	(2 Hz) 0.38 nm(8.5 KHz) 10 nm
Linearity error	<50 nm (full range)	<130 nm (full range)	<130 nm (full range)
Power dissipation	<35 μW	<35 μW	<35 μW
Physical diameter	12 mm	12 mm	8 mm

TypeBrand	IDSH/D4/F13/RTAttocube	IDSH/D4/F8/RTAttocube	IDSH/1/M12/RT/F40/CustAttocube
Nominal measurement range	4 mm	4 mm	4 mm
Gap (min.-max.)	11–15 mm	6–10 mm	38–42 mm
Resolution (relative)	1 pm	1 pm	1 pm
Resolution (absolute)	10–100 microns	10–100 microns	10–100 microns
Repeatability	2 nm	2 nm	2 nm
Wavelength	1530 nm	1530 nm	1530 nm
Physical diameter	4 mm	4 mm	14 mm

Manufacturer, distributor	Zygo, AMETEK Germany GmbH
Model	4-inch Dynafiz plus 12-inch expander
Measuring principle	Phase-shift interferometry
Aperture diameter	304.8 mm
Source	Stabilized He–Ne laser, wavelength 632.8 nm
Repeatability	Repeatability <0.25 nm (2 σ)
Resolution	λ/12000 (high-resolution mode, double pass)
Image size	1200 x 1200 pixels
Digitization	10 bits
Flats quality (calibrated)	12 nm and 18 nm (P–V)
Flats material	Fused silica

TypeBrand	D-510.051Physik Instrumente	CSH1-CAm1.4Micro-Epsilon	CSH05-CAm1.4Micro-Epsilon
Nominal measurement range	50 μm	1000 μm	500 μm
Gap (min.-max.)	25–375 μm	0–1000 μm	0–500 μm
Static resolutionDynamic resolution	(10 Hz) 0.5 nm(10 KHz) 1 nm	(2 Hz) 0.75 nm(8.5 KHz) 20 nm	(2 Hz) 0.38 nm(8.5 KHz) 10 nm
Linearity error	<50 nm (full range)	<130 nm (full range)	<130 nm (full range)
Power dissipation	<35 μW	<35 μW	<35 μW
Physical diameter	12 mm	12 mm	8 mm