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Traceable calibration of Shack–Hartmann wavefront sensors employing spherical wavefronts

25.09.2020

Traceable, highly accurate calibration of wavefront sensors such as Shack–Hartmann sensors is a challenging task and an active field of research. We have developed a measurement system for the traceable calibration of wavefront sensors employing spherical wavefronts and a point light source in combination with a three-axis linear stage. We obtain an absolute calibration of sensor errors, including the reference spot position and wavefront gradient-dependent errors for each microlens individually. We discuss the main error influences and present an initial measurement uncertainty budget for the calibration. The calibration can be performed with an expanded measurement uncertainty (95% coverage interval) of better than 5 μrad for the wavefront gradient deviation.

Traceable, highly accurate calibration of wavefront sensors such as Shack–Hartmann sensors is a challenging task and an active field of research. We have developed a measurement system for the traceable calibration of wavefront sensors employing spherical wavefronts and a point light source in combination with a three-axis linear stage. We obtain an absolute calibration of sensor errors, including the reference spot position and wavefront gradient-dependent errors for each microlens individually. We discuss the main error influences and present an initial measurement uncertainty budget for the calibration. The calibration can be performed with an expanded measurement uncertainty (95% coverage interval) of better than 5 μrad for the wavefront gradient deviation.

Authors:
Johannes Bautsch; 4.2 Imaging and Wave Optics, PTB-Braunschweig
Markus Schake; 4.2 Imaging and Wave Optics, PTB-Braunschweig
Gerd Ehret;  4.2 Imaging and Wave Optics, PTB-Braunschweig
Ulrich Berg; OPTOCRAFT GmbH, Germany
Lorenz Wagner; OPTOCRAFT GmbH, Germany
Johannes Pfund; OPTOCRAFT GmbH, Germany
Rainer Tutsch; Technische Univ. Braunschweig, Germany


For further information:
SPIE Optical Engineering, 59(8), 084104 (2020). https://doi.org/10.1117/1.OE.59.8.084104

Kontakt

Leiter der Presse- und Öffentlichkeitsarbeit

Dr. Dr. Jens Simon

Telefon: (0531) 592-3005
E-Mail:
jens.simon(at)ptb.de

Anschrift

Physikalisch-Technische Bundesanstalt
Bundesallee 100
38116 Braunschweig