Spatial light modulator

About: Spatial light modulator is a research topic. Over the lifetime, 9043 publications have been published within this topic receiving 130143 citations.

Comparison of optical vortex detection methods for use with a Shack-Hartmann wavefront sensor

Abstract: In this paper we compare experimentally two methods of detecting optical vortices from Shack-Hartmann wavefront sensor (SHWFS) data, the vortex potential and the contour sum methods. The experimental setup uses a spatial light modulator (SLM) to generate turbulent fields with vortices. In the experiment, many fields are generated and detected by a SHWFS, and data is analysed by the two vortex detection methods. We conclude that the vortex potential method is more successful in locating vortices in these fields.

Laser-Based Head-Tracked 3D Display Research

Abstract: The construction and operation of two laser-based glasses-free 3D (autostereoscopic) displays that have been carried out within the European Union-funded projects MUTED and HELIUM3D is described in this paper. Both use a multi-user head tracker to direct regions viewer's referred to as exit pupils to viewer's eyes. MUTED employs a direct-view LCD whose backlight comprises novel steering optics and in HELIUM3D image information is supplied by a horizontally-scanned fast light valve whose output is controlled by a spatial light modulator (SLM). The principle of operation, construction and results obtained are described.

Optical system for producing a modulated color image

Abstract: An optical system divides a light source into its component color bands red, green and blue by making the light travel different physical paths, at least two of these paths use stack retardation films and a polarization beamsplitter. By creating distinct paths, each code can be independently processed and combined to form a single path using a polarization splitter and retarder stack. The system preferably includes an input retarder that aligns a first spectrum of a light from a light source, along a first polarization state, and aligns a second spectrum of the light from the light source, along a second polarization state different than the first polarization state, and a beam splitting unit, optically coupled to the input retarder, and including a first beamsplitter that transmits the first spectrum, as a transmitted spectrum, and that reflects the second spectrum, as a reflected spectrum. The system also includes a first spatial light modulator optically coupled to the beam splitting unit, that alters and reflects the transmitted spectrum, as a modulated transmitted spectrum, towards the beam splitting unit, and a second spatial light modulator optically coupled to the beam splitting unit, that alters and reflects the reflected spectrum, as a modulated reflected spectrum, towards the beam splitting unit. The beam splitting unit combines the modulated transmitted spectrum and the modulated reflected spectrum into a combined spectrum.

Nearly diffraction-limited laser focal spot obtained by use of an optically addressed light valve in an adaptive-optics loop

Abstract: We demonstrate correction of laser wavefront distortions by use of an adaptive-optical technique based on a light valve. The setup consists of an achromatic and adjustable-sensitivity wavefront sensor and a wavefront corrector relying on an optically addressed liquid-crystal spatial light modulator. Experimental results with strongly aberrated beams focused close to the diffraction limit are presented for the cw regime. Additional experiments with pulses and measurement of damage thresholds show that this approach is relevant for spatial phase correction of ultraintense laser pulses.

Algorithms for Compensation of Multimode Fiber Dispersion Using Adaptive Optics

Abstract: We propose adaptive algorithms for mitigating inter-symbol interference (ISI) in multimode fiber (MMF) systems using a spatial light modulator (SLM). Minimizing ISI in MMF systems using an SLM has previously been posed as a convex optimization problem. Based on these results, we propose a range of algorithms for adapting the SLM settings. Some of these are shown to converge to the global optimum in the absence of noise. We then propose modified versions of these algorithms to improve resilience to noise and speed of convergence. Simulation results are included, showing that these algorithms open an otherwise closed eye pattern.