Full-color autostereoscopic 3D display system using color-dispersion-compensated synthetic phase holograms

Author(s): Kyongsik Choi, Hwi Kim, and Byoungho Lee

Abstract:

“A novel full-color autostereoscopic three-dimensional (3D) display system has been developed using color-dispersion-compensated (CDC) synthetic phase holograms (SPHs) on a phase-type spatial light modulator. To design the CDC phase holograms, we used a modified iterative Fourier transform algorithm with scaling constants and phase quantization level constraints. We obtained a high diffraction efficiency (~90.04%), a large signal-to-noise ratio (~9.57dB), and a low reconstruction error (~0.0011) from our simulation results. Each optimized phase hologram was synthesized with each CDC directional hologram for red, green, and blue wavelengths for full-color autostereoscopic 3D display. The CDC SPHs were composed and modulated by only one phase-type spatial light modulator. We have demonstrated experimentally that the designed CDC SPHs are able to generate full-color autostereoscopic 3D images and video frames very well, without any use of glasses.”

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Publication: Optics Express (free download)

Issue/Year/DOI: Optics Express, Vol. 12, Issue 21, pp. 5229-5236
doi:10.1364/OPEX.12.005229

Size selective trapping with optical ”cogwheel” tweezers

Author(s): Alexander Jesacher, Severin Fürhapter, Stefan Bernet, and Monika Ritsch-Marte

Abstract:

“We experimentally investigate the size-selective trapping behavior of Laguerre-Gaussian beams (”doughnut-beams”) and ”cogwheel”-shaped beams which are collinear superpositions of two doughnut beams of equal opposite helical index. Experimentally they are created by diffraction of a Gaussian laser beam at a high resolution refractive spatial light modulator (SLM). In the focus of an optical microscope such a beam looks similar to a ”cogwheel”, i.e. the light intensity is periodically modulated around the circumference of a sphere with a precisely adjustable diameter. In an optical tweezers setup these modes can be used to trap particles or cells, provided their sizes exceed the ring diameter by a fixed amount. This promises a convenient method of constructing an optical tweezers system in microscopy which acts as a passive sorter for particles of differing sizes.”

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Publication: Optics Express (free download)

Issue/Year/DOI: Optics Express, Vol. 12, Issue 17, pp. 4129-4135
doi:10.1364/OPEX.12.004129

Observation of the vortex structure of a non-integer vortex beam

Author(s): Jonathan Leach, Eric Yao and Miles J Padgett

Abstract:

“An optical beam with an eilΦ phase structure carries an orbital angular momentum of lħ per photon. For integer l values, the phase fronts of such beams form perfect helices with a single screw-phase dislocation, or vortex, on the beam axis. For non-integer l values, Berry (2004 J. Opt. A: Pure Appl. Opt. 6 259) predicts a complex-phase structure comprising many vortices at differing positions within the beam cross-section. Using a spatial light modulator we produce eilΦ beams with varying l. We examine the phase structure of such beams after propagation through an interference-based phase-measurement technique. As predicted, we observe that for half-integer l values, a line of alternating charge vortices is formed near the radial dislocation. ”

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Publication: New Journal of Physics (free download)

Issue/Year/DOI: New J. Phys. 6 (2004) 71,
doi:10.1088/1367-2630/6/1/071

Multiple Optical Trapping by Means of Diffractive Optical Elements

Author(s): Dan Cojoc, Valentina Emiliani, Enrico Ferrari, Radu Malureanu, Stefano Cabrini, Remo Zaccaria Proiettiand Enzo Di Fabrizio

Abstract:

“In this paper we report multiple optical trapping of microscopic dielectric particles using diffractive optical elements implemented on twisted nematic liquid crystal spatial light modulators. The particles are trapped in arrays disposed in plane or in volume and can be moved independently in x-y-z by changing the configuration of the diffractive optical element. We show also multiple trapping using Laguerre-Gaussian and Gaussian beams simultaneously. The orbital angular momentum of the Laguerre-Gaussian beam is transferred to the particle, making it to move on a circular trajectory defined by the intensity pattern specific to this beam. We use sample cells built with two microscope slides separated by 120 µm with a sticky tape. The space between the two slides is filled with 2 µm diameter silica spheres diluted in water (concentration 0.026% wt). We show that optical trapping is also possible in a small glass capillary with a diameter of 100 µm. ”

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Publication: Japanese Journal of Applied Physics (free download)

Issue/Year/DOI: Jpn. J. Appl. Phys. 43 (2004) pp. 3910-3915
DOI: 10.1143/JJAP.43.3910

Diffractive optical tweezers in the Fresnel regime

Author(s): Alexander Jesacher, Severin Fürhapter, Stefan Bernet, and Monika Ritsch-Marte

Abstract:

“We demonstrate a flexible setup for holographic steering of laser tweezers in microscopy using a high resolution spatial light modulator (SLM). In contrast to other methods, hologram read-out is done in the off-axis Fresnel regime rather than in the typically used on-axis Fourier regime. The diffractive structure is calculated as a Fresnel hologram, such that after reflection at the SLM only the desired first diffraction order is guided to the input of an optical microscope, where it generates a tailored optical tweezers field. We demonstrate some advantageous features of this setup, i.e. undesired diffraction orders are suppressed, the optical traps can be easily steered in real-time by just “mouse-dragging” a hologram window at the SLM display, and a number of independently steerable optical traps can be generated simultaneously in a three-dimensional arrangement by displaying a corresponding number of adjacent hologram windows at the SLM screen.”

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Publication: Optics Express (free download)

Issue/Year/DOI: Optics Express, Vol. 12, Issue 10, pp. 2243-2250
doi:10.1364/OPEX.12.002243

Real time opto-digital holographic microscopy (RTODHM)

Author(s): Larbi Bouamama, Mohamed Bouafia, Guenther Wernicke, Sven Krueger and Hartmut Gruber

Abstract:

“The high development of numerical image and signal processing techniques, may lead to the replacement of conventional photosensitive media used in holography by CCD sensors: hence, to the field of digital holography. The hologram is saved in the host memory of a computer and can be reconstructed on the same place or elsewhere in a numerical manner. The development of liquid crystal displays (LCD) directly addressed by computer permits to think of opto-digital holography. The observation of the reconstructed image at a limited distance is possible when using adequate optical components, which makes not only the possibility to observe the image at a defined distance but also to control its magnification (opto-digital holographic microscopy). Since it is possible to control all experimental steps by adequate software, it is then possible to make real time opto-digital holographic microscopy. In this work, we show the experimental set-up and the obtained results, showing that this technique can be used to study different kinds of materials, connected to different conventional microscopes and to make holographic interferometry.”

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Publication: ScienceDirect.com, (subscription required)

Issue/Year/DOI: Catalysis Today, Volume 89, Issue 3, 30 March 2004, Pages 337-341
doi:10.1016/j.cattod.2003.12.017

Common-path interferometry with one-dimensional periodic filters

Author(s): Victor Arrizón and David Sánchez-de-la-Llave

Abstract:

“We discuss a spatial filtering interferometry setup that employs a periodic spatial filter with either cosine transmittance or binary phase modulation. The setup’s input plane is formed by two separate windows, one of which supports a phase object and the other, a reference beam. Using the appropriate frequency and orientation of the filter produces an interference pattern of the two input fields at the output plane of the system. The main attributes and advantages of the setup are discussed and experimentally illustrated with the example of a binary phase periodic filter implemented with a spatial light modulator.”

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Publication: Optics Letters (subscription required)

Issue/Year/DOI: Optics Letters, Vol. 29, Issue 2, pp. 141-143 (2004)
doi:10.1364/OL.29.000141

Complex modulation with a twisted-nematic liquid-crystal spatial light modulator: double-pixel approach

Author(s): Victor Arrizón

Abstract:

“I modify the double-phase holographic code to implement complex modulation with a transmission twisted-nematic liquid-crystal display. This device is employed in the mostly phase configuration, for which the phase modulation is coupled with a nonconstant amplitude modulation. The modified double-phase code implements arbitrary complex modulation employing the constrained complex modulation of the display.”

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Publication: Optics Letters (subscription required)

Issue/Year/DOI: Optics Letters, Vol. 28, Issue 15, pp. 1359-1361
doi:10.1364/OL.28.001359

Amplitude, Phase, and Hybrid Ternary Modulation Modes of a Twisted-Nematic Liquid-Crystal Display at ~400 nm

Author(s): Judit Reményi, Péter Várhegyi, László Domján, Pál Koppa, and Emõke Lõrincz

Abstract:

“Applicability of a commercial twisted-nematic liquid-crystal display is examined at ~400 nm. Different modulation modes predicted by Jones-matrix calculus are experimentally tested. High contrast amplitude modulation with negligible loss, high contrast and low loss hybrid ternary modulation, and 1.5π continuous phase delay without intensity modulation and with low loss are presented. Simulation results of a 4f holographic system prove the usefulness of the high contrast for amplitude modulation, and the importance of π phase difference between high transmission white levels in a hybrid ternary modulation.”

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Publication: Applied Optics, (subscription required)

Issue/Year/DOI: Applied Optics, Vol. 42, Issue 17, pp. 3428-3434 (2003)
doi:10.1364/AO.42.003428

Optical processing for the detection of faults in interferometric patterns

Author(s): Frank Kallmeyer, Sven Krueger, Guenther Wernicke, Hartmut Gruber, Nazif Demoli, Wolfgang Osten, Daniel Kayser

Abstract:

“The detection and classification of faults is a major task for optical nondestructive testing in industrial quality control. Interferometric fringes, obtained by real-time optical measurement methods, contain a large amount of image data with information about possible defect features. This mass of data must be reduced for further evaluation. One possible way is the filtering of these images applying the adaptive wavelet transform. The wavelet transform has been proved to be a capable tool in the detection of structures with definite spatial resolution. In this paper it is shown the extraction and classification of disturbances in interferometric fringe patterns, the application of several wavelet functions with different parameters for the detection of faults, and the combination of wavelet filters for fault classification. Furthermore the implementation of complex valued wavelet filters and correlation filters is shown. We will present an algorithm to classify interferometric fringe patterns. In order to achieve real-time processing a hybrid opto-electronic system with a digital image processing and an optical correlation module is favored. The calculated wavelet filters are implemented into the optical correlator system that is based on liquid-crystal spatial light modulators. So, all discussed items were verified experimentally in the optical setup. ”

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Publication: SPIE Digital Library, (subscription required)

Issue/Year/DOI: Proc. SPIE, Vol. 4777, 371 (2002);
doi:10.1117/12.472237