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Proceedings Paper

Wavefront analysis and optimization from conventional liquid crystal displays for low-cost holographic optical tweezers and digital holographic microscopy
Author(s): Andreas Weber; Valentin Ortega Clavero; Werner Schröder
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Paper Abstract

In different study fields the manipulation and imaging of micro-sized particles is essential. The use of holographic optical tweezers (HOT) and digital holographic microscopy (DHM) facilitates this task in a non-mechanical way by providing the proper computer generated hologram and the required amount of light. Electrically addressed spatial light modulators (EASLM) found in holographic optical tweezers are typically of the reflective liquid crystal on silicon (LCoS) type which can achieve a phase shift of more than 2π but they are expensive. Similar components like transmissive twisted nematic liquid crystal displays (TN-LCD) are produced in large quantities, their optical characteristics improve rapidly and they are inexpensive. Under certain circumstances these devices can be used instead of expensive spatial light modulators. Consumer grade objectives are not always well corrected for spherical aberration. In that case conventional liquid crystal displays can also compensate these undesired optical effects. For this purpose software-corrected computer generated holograms are calculated. Procedures to analyze and compensate different parameters of a conventional low-cost liquid crystal display, e.g. phase shift evaluation and aberration correction of objectives by Zernike polynomials approximation are explained. The applied software compensation of the computer generated hologram has shown significant improvement of the focus quality. An important price reduction of holographic devices could be achieved by replacing special optical elements if correction algorithms for conventional liquid crystal displays are provided.

Paper Details

Date Published: 20 April 2011
PDF: 9 pages
Proc. SPIE 8065, SPIE Eco-Photonics 2011: Sustainable Design, Manufacturing, and Engineering Workforce Education for a Green Future, 80650W (20 April 2011); doi: 10.1117/12.882918
Show Author Affiliations
Andreas Weber, Univ. of Applied Sciences Offenburg (Germany)
Valentin Ortega Clavero, Univ. of Applied Sciences Offenburg (Germany)
Werner Schröder, Univ. of Applied Sciences Offenburg (Germany)


Published in SPIE Proceedings Vol. 8065:
SPIE Eco-Photonics 2011: Sustainable Design, Manufacturing, and Engineering Workforce Education for a Green Future
Pierre Ambs; Dan Curticapean; Claus Emmelmann; Wolfgang Knapp; Zbigniew T. Kuznicki; Patrick P. Meyrueis, Editor(s)

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