Compact design for optical-see-through holographic displays employing holographic optical elements

Author(s):

Pengcheng Zhou and Yan Li and Shuxin Liu and Yikai Su

Abstract:

“Holographic AR display is a promising technology for head-mounted display
devices. However, it usually has a complicated optical system and a large form factor, preventing it from widespread applications. In this work, we propose a flat-panel design to produce a compact holographic AR display, wh
ere traditional optical elements are replaced by two holographic optical elements (HOEs). Here, these two thin HOEs together perform the optical functions of a beam expander, an ocular lens, and an optical combiner. Without any bulky traditional optics, our design could achieve a compact form factor that is similar to a
pair of glasses. We also implemented a proof-of-concept prototype to verify its feasibility. Being compact, lightweight and free from accommodation-conve
rgence discrepancy, our design is promising for fatigue-free AR displays.”

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Publication: Optics Express

Issue/Year/DOI: Optics Express Volume 26, Issue 18
DOI: 10.1364/OE.26.022866

Accelerated generation of holographic videos of 3-D objects in rotational motion using a curved hologram-based rotational-motion compensation method

Author(s):

Hong-Kun Cao and Shu-Feng Lin and Eun-Soo KimAbstract:

“Abstract: A new curved hologram-based rotational-motion compensation (CH-RMC) method is proposed for accelerated generation of holographic videos of 3-D objects moving on the random path with many locally different arcs. All of those rotational motions of the object made on each arc can be compensated, just by rotating their local curved holograms along the curving surfaces matched with the object’s moving trajectory without any additional calculation process, which results in great enhancements of the computational speed of the conventional hologram-generation algorithms. Experiments with a test video scenario reveal that average numbers of calculated object points (ANCOPs) and average calculation times for one frame (ACTs) of the CH-RMC-based ray-tracing, wavefront-recording-plane and novel- look-up-table methods have been found to be reduced by 73.10%, 73.84%, 73.34%, and 68.75%, 50.82%, 66.59%, respectively, in comparison with those of their original methods. In addition, successful reconstructions of 3-D scenes from those holographic videos confirm the feasibility of the proposed system. ”

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Publication: Optics Express
Issue/Year/DOI: Optics Express Volume 26, Issue 16 pp. 21279-21300 (2018)
DOI: 10.1364/oe.26.021279

Demonstration of a vectorial optical field generator with adaptive close loop control

Author(s):

Jian Chen and Lingjiang Kong and Qiwen Zhan

Abstract:

“We experimentally demonstrate a vectorial optical field generator (VOF-Gen) with an adaptive close loop control. The close loop control capability is illustrated with the calibration of polarization modulation of the system. To calibrate the polarization ratio modulation, we generate 45° linearly polarized beam and make it propagate through a linear analyzer whose transmission axis is orthogonal to the incident beam. For the retardation calibration, circularly polarized beam is employed and a circular polarization analyzer with the opposite chirality is placed in front of the CCD as the detector. In both cases, the close loop control automatically changes the value of the corresponding calibration parameters in the pre-set ranges to generate the phase patterns applied to the spatial light modulators and records the intensity distribution of the output beam by the CCD camera. The optimized calibration parameters are determined corresponding to the minimum total intensity in each case. Several typical kinds of vectorial optical beams are created with and without the obtained calibration parameters, and the full Stokes parameter measurements are carried out to quantitatively analyze the polarization distribution of the generated beams. The comparisons among these results clearly show that the obtained calibration parameters could remarkably improve the accuracy of the polarization modulation of the VOF-Gen, especially for generating elliptically polarized beam with large ellipticity, indicating the significance of the presented close loop in enhancing the performance of the VOF-Gen.”

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Publication: Review of Scientific Instruments

Issue/Year/DOI: Review of SCientific Instruments 88, 125111 (2017)
DOI: 10.1063/1.4999656

Tightly focused optical field with controllable photonic spin orientation

Author(s):

Jian Chen and Chenhao Wan and Ling Jiang Kong and Qiwen Zhan

Abstract:

“The spin angular momentum of photons offers a robust, scalable and highbandwidth
toolbox for many promising applications based upon spin-controlled
manipulations of light. In this work, we develop a method to achieve controllable photonic
spin orientation within a diffraction limited optical focal spot produced by a high numerical
aperture objective lens. The required pupil field is found analytically through reversing the
radiation patterns from two electric dipoles located at the focal point of the lens with
orthogonal oscillation directions and quadrature phase. The calculated pupil fields are
experimentally generated with a vectorial optical field generator. The produced photonic spin
orientations are quantitatively evaluated by their spin densities according to the tightly
focused electric fields calculated by Richard-Wolf vectorial diffraction theory to demonstrate
the validity and capability of the proposed technique.”

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Publication: Optics Express

Issue/Year/DOI: Optics Express, Volume 25, Number 16 pp. 19517-19528 (2017)
DOI: 10.1364/OE.25.019517

What spatial light modulators can do for optical microscopy

Author(s): C. Maurer, A. Jesacher, S. Bernet, M. Ritsch-Marte.

Abstract:

“With the availability of high-resolution miniature spatial light modulators (SLMs) new methods in optical microscopy have become feasible. The SLMs discussed in this review consist of miniature liquid crystal displays with micron-sized pixels that can modulate the phase and/or amplitude of an optical wavefront. In microscopy they can be used to control and shape the sample illumination, or they can act as spatial Fourier filters in the imaging path. Some of these applications are reviewed in this article. One of them, called spiral phase contrast, generates isotropic edge enhancement of thin phase samples or spiral-shaped interference fringes for thicker phase samples, which can be used to reconstruct the phase topography from a single on-axis interferogram. If SLMs are used for both illumination control and spatial Fourier filtering, this combination for instance allows for the generalization of the Zernike phase contrast principle. The new SLM-based approach improves the effective resolution and avoids some shortcomings and artifacts of the traditional method. The main advantage of SLMs in microscopy is their flexibility, as one can realize various operation modes in the same setup, without the need for changing any hardware components, simply by electronically switching the phase pattern displayed on the SLMs.”

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Publication: Laser & Photonics Reviews, (subscription required)

Issue/Year/DOI: Laser & Photonics Reviews, Volume 5, Issue 1, pages 81–101, January 2011
DOI: 10.1002/lpor.200900047

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.”

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Publication: Optics Express, (free download)

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

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 (free download)

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

Phase Contrast Projection Display Using Photopolymer

Author(s): Piao, Mei-Lan; Kim, Nam; Park, Jae-Hyeung

Abstract:

“We propose a phase contrast filter using photopolymer, for the phase contrast projection display. The photopolymer has high photosensitivity such that its optically induced refractive index change has a linear dependency on the illuminating light intensity. We implemented a phase contrast projection display using photopolymer as a phase contrast filter. By controlling the refractive index change of the photopolymer, we successfully convert an input phase image into a high contrast intensity image. We also investigated the effect of the photopolymer illumination condition on the quality of the displayed intensity image. As a projector, we achieved 82% phase to intensity conversion efficiency, which implies that the proposed method can potentially have much higher light efficiency than conventional projection display.”

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Publication: Journal of the Optical Society of Korea, (free download)

Issue/Year/DOI: Journal of the Optical Society of Korea, Volume 12, Issue 4, December 2008, pp.319-325
DOI : 10.3807/JOSK.2008.12.4.319

A spatial light phase modulator with an effective resolution of 4 mega-pixels

Author(s): Daryl Preece; Eric Yao; Graham Gibson; Richard Bowman; Jonathan Leach; Miles Padgett

Abstract:

“We report the design, construction and characterization of a 4 mega-pixel, optically-addressed, spatial light modulator (OSLM). The intensity distribution corresponding to a kinoform is displayed across two wide-screen liquid crystal on silicon displays, the images of which are combined and relayed to the address face of a 40 mm aperture OSLM. This spatially varying intensity profile is converted into a phase hologram on the readout side of the OSLM. When illuminated at 532 nm we measure a first-order diffraction efficiency of ≈50% at 400 line pairs and ≈20% at 900 line pairs. We show that aberration associated with the non-flatness of the device can be corrected within software by modification of the hologram.”

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Publication: Journal of Modern Optics, (subscription required)

Issue/Year/DOI: Journal of Modern Optics, Volume 55, Issue 18 October 2008 , pages 2945 – 2951
DOI: 10.1080/09500340802272357

Collisions of Dark Solitons in Elongated Bose-Einstein Condensates

Author(s): S. Stellmer, C. Becker, P. Soltan-Panahi, E.-M. Richter, S. Dörscher, M. Baumert, J. Kronjäger, K. Bongs, and K. Sengstock

Abstract:

“We present experimental data showing the head-on collision of dark solitons generated in an elongated Bose-Einstein condensate. No discernable interaction can be recorded, in full agreement with the fundamental theoretical concepts of solitons as mutually transparent quasiparticles. Our soliton generation technique allows for the creation of solitons with different depths; hence, they can be distinguished and their trajectories be followed. Simulations of the 1D-Gross-Pitaevskii equation have been performed to compare the experiment with a mean-field description.”

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Publication: Physical Review Letters, (subscription required)

Issue/Year/DOI: Phys. Rev. Lett. 101, Issue 12, 120406 (2008)
doi:10.1103/PhysRevLett.101.120406