3-D coherence holography using a modified Sagnac radial shearing interferometer with geometric phase shift

Author(s): Dinesh N. Naik, Takahiro Ezawa, Yoko Miyamoto, and Mitsuo Takeda

Abstract:

“A new image reconstruction scheme for coherence holography using a modified Sagnac-type radial shearing interferometer with geometric phase shift is proposed, and the first experimental demonstration of generic Leith-type coherence holography, which reconstructs off-axis 3-D objects with depth information, is presented. The reconstructed image, represented by a coherence function, can be visualized with a controllable magnification, which opens up a new possibility for a coherence imaging microscope.”

Link to Publications Page

Publication: Optics Express
Issue/Year: Optics Express, Vol. 17, Issue 13, pp. 10633-10641
DOI: 10.1364/OE.17.010633

Experimental investigation of holographic 3D-TV approach

Author(s): Agour, M., and Kreis, T.

Abstract:

“A digital hologram is recorded by a 2D CCD array by superposition of the wavefield reflected or scattered from a scene and a coherent reference wave. If the recorded digital hologram is fed to a spatial light modulator (SLM) and this is illuminated by the reference wave, then the whole original wavefield can be reconstructed. The reconstructed wavefield contains phase and intensity distributions, which means it is full 3D, exhibiting such effects as depth and parallax. Therefore, the concept of digital holography is a promising approach to 3D-TV. In one of our previous works the preliminaries of an all-digital-holographic approach to 3D-TV were given. Here one of our approaches is experimentally verified and its capabilities and limitations are investigated.”

Link to Publications Page

Publication: Paper 3DTV Conference
Issue/Year: 3DTV Conference: The True Vision – Capture, Transmission and Display of 3D Video, (2009)
DOI: 10.1109/3DTV.2009.5069652

Ghost imaging with a single detector

Author(s): Yaron Bromberg, Ori Katz, Yaron Silberberg

Abstract:

“We experimentally demonstrate pseudothermal ghost imaging and ghost diffraction using only a single detector. We achieve this by replacing the high-resolution detector of the reference beam with a computation of the propagating field, following a recent proposal by Shapiro [ Phys. Rev. A 78, 061802(R) (2008)]. Since only a single detector is used, this provides experimental evidence that pseudothermal ghost imaging does not rely on nonlocal quantum correlations. In addition, we show the depth-resolving capability of this ghost imaging technique.”

Link to Publications Page

Publication: Physical Review A
Issue/Year: Phys. Rev. A, Volume 79, Issue 5, 053840 (2009)
DOI: 10.1103/PhysRevA.79.053840

Microdisplays in holographic mastering applications

Author(s): Sven Plöger, Sven Krüger, Stefan Osten, Günther Wernicke

Abstract:

“We demonstrate implementation and performance of microdisplay systems based on liquid-crystal technology in a variety of applications in holographic mastering. These displays can encode 2D objects information in grey scale or address holographic patterns in amplitude or phase. The main advantage is here to address any content dynamically with typically 60 Hz. Furthermore they show a resolution up to 1920×1200 pixels with a pixel size as small as 6.4 microns. Therefore they are extremely suitable for a dynamic or multi-exposure mastering process, to incorporate image content, phase-encode objects or any holographic features. This technology is already being used in holographic security applications as well as in commercial and display holography. We report about a few applications/implementations and show experimental results and performance parameters.”

Link to Publications Page

Publication: SPIE Proceedings
Issue/Year: Proc. SPIE, Vol. 7358, 73581H (2009);
DOI: 10.1117/12.823474

Poincaré-sphere representation of phase-mostly twisted nematic liquid crystal spatial light modulators

Author(s): V Durán, P Clemente, Ll Martínez-León, V Climent, J Lancis

Abstract:

“We establish necessary conditions in order to build a phase-only wavefront modulation system from a liquid crystal display. These conditions determine the dependence of the polarization state of the light emerging from the display on the addressing gray level. The analysis, which is carried out by means of the coherence-matrix formalism, includes the depolarization properties of the device. Two different types of polarization distributions at the output of the liquid crystal cells are found. This approach is applied to a twisted nematic liquid crystal display. In this case, an optimization algorithm must be designed in order to select the input polarization state that leads to the required distributions. We show that the Poincaré-sphere representation provides a convenient framework to design the optimization algorithm as it allows for a reduced number of degrees of freedom. This feature significantly decreases the computation time. Laboratory results are presented for a liquid crystal on silicon display showing a phase modulation depth greater than 2π rad with an intensity variation lower than 6%. In addition, a hybrid ternary modulation (HTM), an operation regime employed in holographic data storage, is achieved.”

Link to Publications Page

Publication: Journal of Optics A
Issue/Year: J. Opt. A: Pure Appl. Opt. (2009), Opt. 11 085403
DOI: 10.1088/1464-4258/11/8/085403

Influence of the incident angle in the performance of Liquid Crystal on Silicon displays

Author(s): A. Lizana, N. Martín, M. Estapé, E. Fernández, I. Moreno, A. Márquez, C. Iemmi, J. Campos, and M. J. Yzuel

Abstract:

“In this paper we experimentally analyze the performance of a twisted nematic liquid crystal on silicon (LCoS) display as a function of the angle of incidence of the incoming beam. These are reflective displays that can be configured to produce amplitude or phase modulation by properly aligning external polarization elements. But we demonstrate that the incident angle plays an important role in the selection of the polarization configuration. We performed a Mueller matrix polarimetric analysis of the display that demonstrates that the recently reported depolarization effect observed in this type of displays is also dependant on the incident angle. ”

Link to Publications Page

Publication: Optics Express
Issue/Year: Optics Express, Vol. 17, Issue 10, pp. 8491-8505 (2009)
DOI: 10.1364/OE.17.008491

Position and Intensity Modulations in Holographic Optical Traps Created by a Liquid Crystal Spatial Light Modulator

Author(s): Astrid van der Horst, Benjamin P. Downing, and Nancy R. Forde

Abstract:

“The addressing of the liquid crystals in spatial light modulators gives rise to temporal modulation of the phase pattern. Here we investigate the effect of this on the intensity and position of holographic optical traps.”

Link to Publications Page

Publication: Optical Trapping Applications 2009
Issue/Year: Advances in Imaging, OSA Technical Digest (CD) (Optical Society of America, 2009), paper OMB3
DOI: 10.1364/OTA.2009.OMB3

Programmable ultrashort-pulsed flying images

Author(s): M. Bock, S. K. Das, and R. Grunwald

Abstract:

“We report the generation of programmable two-dimensional arrangements of ultrashort-pulsed fringe-less Bessel-like beams of extended depth of focus (referred to as needle beams) without truncating apertures. A sub-20-fs Ti:sapphire laser and a liquid-crystal-on-silicon spatial light modulator (LCoS-SLM) of high-fidelity temporal transfer in phase-only operation mode were used in the experiments. Axicon profiles with ultrasmall conical angles were approximated by adapted gray scale distributions. It was demonstrated that digitized image information encoded in amplitudephase maps of the needle beams is propagated over considerably large distances at minimal cross talk without the need for additional relay optics. This experiment represents a physical realization of Saari’s proposal of spatio-temporally nondiffracting “flying images” on a few-femtosecond time scale. ”

Link to Publications Page

Publication: Optics Express
Issue/Year: Optics Express, Vol. 17, Issue 9, pp. 7465-7478
DOI: 10.1364/OE.17.007465

Model-free method for measuring the full Jones matrix of reflective liquid-crystal displays

Author(s): Christian Kohler, Tobias Haist, Wolfgang Osten

Abstract:

“We present a method for measuring all eight parameters (including the signs) of the Jones matrices of liquid-crystal displays. The method can be applied to measure the Jones matrices for all addressable gray levels thus delivering the specifications needed for calculating characteristic curves for arbitrary input and output polarizations. Unlike other approaches, we do not rely on a physical model of the LCD. Thus, it is possible to measure the Jones matrices of a more complex optical system in one step (e.g., when a reflective LCD is used in combination with a beamsplitter). Though the method presented is, in principle, applicable for transmissive and reflective LCDs, calculations and experiments are only shown using the example of a reflective liquid-crystal-on-silicon display. ”

Link to Publications Page

Publication: SPIE – Optical Engineering
Issue/Year: SPIE – Optical Engineering, Vol. 48, 044002 (2009)
DOI: 10.1117/1.3119309

Sagnac-interferometer-based characterization of spatial light modulators

Author(s): Jian Wei Tay, Michael A. Taylor, Warwick P. Bowen

Abstract:

“A method for characterizing the phase response of spatial light modulators (SLMs) by using a Sagnac interferometer is proposed and demonstrated. The method represents an improvement over conventional diffraction-based or interferometric techniques by providing a simple and accurate phase measurement while taking advantage of the inherent phase stability of a Sagnac interferometer. As a demonstration, the phase response of a commercial liquid crystal on a silicon SLM is characterized and then linearized by using a programmable lookup table. The transverse phase profile over the SLM surface is also measured.”

Link to Publications Page

Publication:Applied Optics
Issue/Year: Applied Optics, Vol. 48, Issue 12, pp. 2236-2242 (2009)
DOI: 10.1364/AO.48.002236
1 … 45 46 47 48 49 … 64