Sensors & Transducers
Vol. 247, Issue 8, December 2020, pp. 8-17
_______________
Advanced Measurement Procedure for Interferometric Microscope for Three-dimensional Imaging of Complex Surfaces Using
​Two-wavelength Interferometry and Reference Arm Attenuation
1, *
Marek Stašík,
1
František Kaván,
2
Marek Mach,
1
Karolína Sedláčková,
​
1
Jan Kredba and
2
Michal Špína
1
Technical University of Liberec, Institute of New Technologies and Applied Informatics, Studentská 1402/2, 461 17 Liberec, Czech Republic
2
Regional Centre for Special Optics and Optoelectronic Systems (TOPTEC), Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 1782/3, 182 00 Prague 8, Czech Republic
*
Tel.: 420604534584
* E-mail: marek.stasik@tul.cz
Received: 9 November 2020 /Accepted: 15 December 2020 /Published: 31 December 2020
Abstract:
Digital holographic microscopy is a powerful 3D imaging tool for industrial surface inspection and scientific experiment evaluation, as it provides lateral resolution similar to classical microscopy and very fine axial resolution. This paper presents the results and the findings of experimental holographic microscope development. The device construction is described. The research emphasises on two- wavelength interferometry combined with phase shifting. The phase shifting was done using acousto-optic modulators, which allow precise tuning of light frequency. A developed enhanced measurement procedure which increases versatility by increasing dynamic range is described. Developed algorithms for data evaluation are presented and measured experimental data visualised.
Keywords:
Microscope, Interferometry, Phase shifting, Bragg cell, Acousto-optic modulator, Multiwavelength interferometry, High dynamic range.
.__________________________________________________________________________________________