Femtosecond pulse shaping using a liquid–crystal display: Applications to depth profiling analysis

Author(s): Ota Samek, Vanja Hommes, Roland Hergenröder, Sergei V. Kukhlevsky

Abstract:

“We report on a beam shaping technique for femtosecond laser pulses based on a liquid-crystal display. The system is capable of modifying femtosecond Gaussian beams to a flattop beam. A pattern projected onto liquid-crystal display modifies the incoming Gaussian beam intensity so that flattop intensity profile is obtained. The process is monitored online using a charge-coupled device camera so that the intensity distribution of each pulse is known. An experimental example of the depth profile of a Cr layer on a Si substrate obtained using such a modified beam is presented.”

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Publication: Review of Scientific Instruments
Issue/Year: Rev. Sci. Instrum. 76, 086104 (2005)
DOI: 10.1063/1.1994897

Encoding fully-complex transmittance with coupled amplitude-phase liquid-crystal modulator

Author(s): Victor M. Arrizón, Luis A. Gonzalez Lopez

Abstract:

“We propose a holographic code for synthesis of fully-complex transmittance, which can be implemented employing a twisted-nematic liquid-crystal display, two linear polarizers, and a He-Ne laser. This simple setup provides a reduced phase range and amplitude modulation with significant variance. Our holographic code efficiently exploits this constrained modulation for the accurate encoding of arbitrary complex transmittance. Two experimental examples illustrate the good performance of the holographic code.”

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Publication: SPIE – Optical Engineering
Issue/Year: Opt. Eng., Vol. 44, 070502 (2005)
DOI: 10.1117/1.1978427

Compensation for pixel-mismatch errors in shift-multiplexed holographic data storage

Author(s): Sungphil Kim, Seok Ho Song, Jideog Kim, and Hong-Seok Lee

Abstract:

“To read out correct data from shift-multiplexed holographic data storage, we propose a novel method of pixel matching by use of a tiny plane-parallel refraction plate placed in the path of converging readout beams. Tilting the refraction plate produces a shift in the lateral position of the readout beam incident upon the holographic storage disk, leading to compensation for pixel-mismatch errors by an improvement in bit-error rate of 3 orders of magnitude.”

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Publication: Optics Letters
Issue/Year: Optics Letters, Vol. 30, Issue 7, pp. 771-773 (2005)
DOI: 10.1364/OL.30.000771

Computer-generated holograms with optimum bandwidths obtained with twisted-nematic liquid-crystal displays

Author(s): Victor Arrizón, Luis A. González, Rodrigo Ponce, and Alfonso Serrano-Heredia

Abstract:

“We discuss a computer-generated hologram for encoding arbitrary complex modulation based on a commercial twisted-nematic liquid-crystal display. This hologram is implemented with the constrained complex modulation provided by the display in a phase-mostly configuration. The hologram structure and transmittance are determined to obtain on-axis signal reconstruction, maximum bandwidth, optimum efficiency, and high signal-to-noise ratio. We employed the proposed holographic code for the experimental synthesis of first-order Bessel beams.”

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Publication: Applied Optics
Issue/Year: Applied Optics, Vol. 44, Issue 9, pp. 1625-1634, 2005
DOI: 10.1364/AO.44.001625

Structure and scaling of helical modes of light

Author(s): Steven Sundbeck, Ilya Gruzberg, and David G. Grier

Abstract:

“Modes of light that contain topological defects such as screw dislocations can be focused into optical traps with interesting and useful properties. The way in which the intensity distribution within helical modes of light varies with topological charge is discussed, and new scaling predictions for their radial profiles that are consistent with experimental observations are introduced.”

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Publication: Optics Letters
Issue/Year: Optics Letters, Vol. 30, Issue 5, pp. 477-479 , 2005
DOI: 10.1364/OL.30.000477

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
Issue/Year: Optics Express, Vol. 12, Issue 21, pp. 5229-5236, 2004
DOI: 10.1364/OPEX.12.005229

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

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:Catalysis Today
Issue/Year: Catalysis Today, Volume 89, Issue 3, 30 March 2004, Pages 337-341, 2004
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
Issue/Year: 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
Issue/Year: Optics Letters, Vol. 28, Issue 15, pp. 1359-1361, 2003
DOI: 10.1364/OL.28.001359
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