Three-dimensional parallel holographic micropatterning using a spatial light modulator

Author(s): Nathan J. Jenness, Kurt D. Wulff, Matthew S. Johannes, Miles J. Padgett, Daniel G. Cole, and Robert L. Clark

Abstract:

“We present a micropatterning method for the automatic transfer and arbitrary positioning of computer-generated three-dimensional structures within a substrate. The Gerchberg-Saxton algorithm and an electrically addressed spatial light modulator (SLM) are used to create and display phase holograms, respectively. A holographic approach to light manipulation enables arbitrary and efficient parallel photo-patterning. Multiple pyramidal microstructures were created simultaneously in a photosensitive adhesive. A scanning electron microscope was used to confirm successful replication of the desired microscale structures. ”

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Publication: Optics Express
Issue/Year: Optics Express, Vol. 16, Issue 20, pp. 15942-15948 (2008)
DOI: 10.1364/OE.16.015942

Novel approaches to the design of halftone masks for analog lithography

Author(s): Marcel Teschke and Stefan Sinzinger

Abstract:

“We report novel approaches to the design of halftone masks for analog lithography. The approaches are derived from interferometric phase contrast. In a first step we show that the interferometric phase-contrast method with detour holograms can be reduced into a single binary mask. In a second step we introduce the interferometric phase-contrast method by interference of the object wavefront with the conjugate object wavefront. This method also allows for a design of a halftone mask. To use kinoform holograms as halftone phase masks, we show in a third step the combination of the zeroth-order phase-contrast technique with the interferometric phase-contrast method.”

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Publication: Applied Optics
Issue/Year: Applied Optics, Vol. 47, Issue 26, pp. 4767-4776 (2008)
DOI: 10.1364/AO.47.004767

Hologram optimization for SLM-based reconstruction with regard to polarization effects

Author(s): C. Kohler, T. Haist, X. Schwab, and W. Osten

Abstract:

“We report on first results obtained with two modified hologram optimization algorithms. These algorithms take into account the complex modulation characteristic of the spatial light modulators employed for hologram reconstruction. To this end the Jones matrices of the modulator as well as all other components of the setup are used within a modified direct binary search and an iterative Fourier transform algorithm. Geometrical phase effects are included in the optimization. Elimination of the analyzer behind the spatial light modulator is possible by that approach and for typical setups using twisted-nematic liquid crystal modulators an enhanced overall diffraction efficiency is achieved. Possible applications are the comparative digital holography and optical tweezers. Experimental results for the reconstructions of holograms with a Holoeye LC-R 3000 modulator are presented.”

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Publication: Optics Express
Issue/Year: Optics Express, Vol. 16, Issue 19, pp. 14853-14861 (2008)
DOI: 10.1364/OE.16.014853

A new method for three-dimensional tracking using a liquid crystal on silicon (LCoS)

Author(s): Matías A Goldin, Guadalupe Díaz Costanzo, Oscar E Martínez, Claudio Iemmi, Silvia Ledesma

Abstract:

“Imaging of samples by different microscopy techniques has produced a relevant impact in the development of new diagnosis techniques in biology, medicine, and material science. In many biological applications, where the sample changes or moves during the observation, a dynamical focusing of the microscope is needed. To this end it is necessary to localize the sample previously to the refocusing process. We introduce here an optical system that can perform three-dimensional (3D) tracking without mechanical displacements. The system is based on the use of a high resolution liquid crystal on silicon (LCoS) device working as a phase mostly wavefront modulator. The additional advantage of this system is performing the motion of the spot at video rate. By using elliptical polarization we have experimentally found a configuration where the phase modulation is 2π and the intensity modulation has a variation less than 25%. For this configuration we show how the spot can be moved through the focus plane by means of linear phases, or displaced out of this plane by using a quadratic phase.”

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Publication: Journal of Optics A
Issue/Year: J. Opt. A: Pure Appl. Opt., Volume 10, Number 10, pp. 104001
DOI: 10.1088/1464-4258/10/10/104001

Suppression of undesired diffraction orders of binary phase holograms

Author(s): Christian Maurer, Andreas Schwaighofer, Alexander Jesacher, Stefan Bernet, Monika Ritsch-Marte

Abstract:

“A method to remove undesired diffraction orders of computer-generated binary phase holograms is demonstrated. Normally, the reconstruction of binary Fourier holograms, made from just two phase levels, results in an undesired inverted image from the minus first diffraction order, which is superposed with the desired one. This can be avoided by reconstructing the hologram with a diffuse light field with a pseudorandom, but known, phase distribution, which is taken into account for the hologram computation. As a consequence, only the desired image is reconstructed, whereas all residual light is dispersed, propagating as a diffuse background wave. The method may be advantageous to employ ferroelectric spatial light modulators as holographic display devices, which can display only binary phase holograms, but which have the advantage of fast switching rates.”

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Publication: Applied Optics
Issue/Year: Applied Optics, Vol. 47, Issue 22, pp. 3994-3998 (2008)
DOI: 10.1364/AO.47.003994

Holographic Reconstructions Using Phase-Only Spatial Light Modulators

Author(s): Fahri Yaras, Metodi Kovachev, Rossitza Ilieva, Mostafa Agour, Levent Onural

Abstract:

“Phase-only spatial light modulators are used for reconstructions from inline phase holograms that are calculated by Gerchberg-Saxton iterative algorithm. Although iterative procedures are slow in computing holograms, we obtained sufficient results with a rather low number of iterations. We have shown that reconstruction of 2D objects whose sizes are larger than SLM size is possible. Not only single plane 2D objects but also several objects in different depths are reconstructed using phase holograms by superposing their complex diffraction patterns. Results of both numerical and optical reconstructions from phase holograms are satisfactory.”

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Publication:3DTV Conference: The True Vision – Capture, Transmission and Display of 3D Video
Issue/Year: 3DTV Conference: The True Vision – Capture, Transmission and Display of 3D Video, 2008
DOI: 10.1109/3DTV.2008.4569826

Prediction of phase-mostly modulation for holographic optical tweezers

Author(s): J. Andilla , E. Martín-Badosa, S. Vallmitjana

Abstract:

“We characterize a reflective Holoeye LC-R 2500 spatial light modulator with a technique in which Jones matrices describing its polarization capabilities are obtained and then used for any arbitrary configuration. We apply this method to predict a phase-mostly modulation response with minimum amplitude contrast and a phase modulation range close to 2π rad. This allows us to generate multiple traps in a holographic optical tweezers setup with high light efficiency and hardly any unwanted energy on the zero diffraction order.”

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Publication: Optics Communications
Issue/Year: Optics Communications, Volume 281, Issue 14, 15 July 2008, Pages 3786-3791
DOI: 10.1016/j.optcom.2008.03.067

High throughput diffractive multi-beam femtosecond laser processing using a spatial light modulator

Author(s): Zheng Kuang, Walter Perrie, Jonathan Leach, Martin Sharp, Stuart P. Edwardson, Miles Padgett, Geoff Dearden and Ken G. Watkins

Abstract:

“High throughput femtosecond laser processing is demonstrated by creating multiple beams using a spatial light modulator (SLM). The diffractive multi-beam patterns are modulated in real time by computer generated holograms (CGHs), which can be calculated by appropriate algorithms. An interactive LabVIEW program is adopted to generate the relevant CGHs. Optical efficiency at this stage is shown to be ~50% into first order beams and real time processing has been carried out at 50 Hz refresh rate. Results obtained demonstrate high precision surface micro-structuring on silicon and Ti6Al4V with throughput gain >1 order of magnitude.”

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Publication: Applied Surface Science
Issue/Year: Applied Surface Science, Volume 254 – 2008 (2008)
DOI: 10.1016/j.apsusc.2008.07.091

A Projection System for Real World Three-Dimensional Objects Using Spatial Light Modulators

Author(s): Gopinathan, U. Monaghan, D.S. Hennelly, B.M. McElhinney, C.P. Kelly, D.P. McDonald, J.B. Naughton, T.J. Sheridan, J.T.

Abstract:

“We discuss a projection system for real world three-dimensional objects using spatial light modulators (SLM). An algorithm to encode the digital holograms of real world objects on to an SLM is presented. We present results from experiments to project holograms of real world holograms using a nematic liquid crystal SLM. We discuss the case when the pixel sizes of the charge-coupled device (CCD) and SLM used for recording the hologram and projection are different.”

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Publication: Journal of Display Technology
Issue/Year: Journal of Display Technology, Volume 4, Issue 2, June 2008, Pages 254-261
DOI: 10.1109/JDT.2007.913943

Applying SLODAR to measure aberrations in the eye

Author(s): Andrew Lambert, Benjamin J. Birt, David A. Atchison, and Huanqing Guo

Abstract:

“As a proof of concept we apply a technique called SLODAR as implemented in astronomy to the human eye. The technique uses single exposures of angularly separated “stars” on a Hartmann-Shack sensor to determine a profile of aberration strength localised in altitude in astronomy, or path length into the eye in our application. We report on the success of this process with both model and real human eyes. There are similarities and significant differences between the astronomy and vision applications.”

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Publication: Optics Express
Issue/Year: Optics Express, Vol. 16, Issue 10, pp. 7309-7322, 2008
DOI: 10.1364/OE.16.007309
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