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• Introducing a MPC MOSLM containing a birefringent electro-optical material. • The direction of the voltage applied to the structure is an important issue. • The MPC is very thin with MO rotation above 90° and almost complete reflection. • The MOSLM has a large color variety, suitable for display applications. • The different colors are easily created by changing the voltage of the subpixels. Spatial light modulators (SLMs) utilize components such as magnetophotonic crystals (MPCs) to alter specific characteristics of a light beam in space. In magneto-optical (MO) spatial light modulators, MPCs play a crucial role in spatially modulating light by manipulating local light intensity and polarization rotation. This study explores how the refractive indices of birefringent electro-optical materials within MPCs influence MO rotation and reflection. In this order, using a transfer matrix method, we designed thin MPCs with a MO rotation around 90° and almost full reflection, for having SLMs with high contrast. The direction of applied voltage to the structure was found to be a critical factor, leading to significant reduction in power consumption for SLMs incorporating the MPCs. These characteristics render the designed MO spatial light modulator well-suited for applications in projectors and displays. [ABSTRACT FROM AUTHOR]

A novel structure using dielectric separation and local electric field enhancement is proposed to reduce the fringing field effect of high-resolution spatial light modulators (SLMs). In our configuration, photoreactive wall structures are used to suppress the crosslink effect of liquid crystal (LC) molecules between adjacent pixels, and slit-step electrodes can enhance the local electric field, which compensate the disclination caused by the split of fringing electric field. The phase modulation of conventional and novel configurations were simulated, and the effect of LC alignment azimuthal angle was analyzed. The results show that the phase modulation characteristics are greatly improved, which indicates the proposed configuration can suppress the annoying interpixel coupling of SLM sufficiently. [ABSTRACT FROM AUTHOR]

A time multiplexed rectangular Zernike modal wavefront sensor based on a nematic phase-only liquid crystal spatial light modulator and specially designed for a high power two-electrode tapered laser diode which is a compact and novel free space optical communication source is used in an adaptive beam steering free space optical communication system, enabling the system to have 1.25 GHz modulation bandwidth, 4.6° angular coverage and the capability of sensing aberrations within the system and caused by atmosphere turbulence up to absolute value of 0.15 waves amplitude and correcting them in one correction cycle. Closed-loop aberration correction algorithm can be implemented to provide convergence for larger and time varying aberrations. Improvement of the system signal-to-noise-ratio performance is achieved by aberration correction. To our knowledge, it is first time to use rectangular orthonormal Zernike polynomials to represent balanced aberrations for high power rectangular laser beam in practice. [ABSTRACT FROM PUBLISHER]

A free space optical wireless communication system with 3 degree angular coverage and 1.25 GHz modulation bandwidth is reported, in which relatively narrow laser beam of a simultaneous high power, high modulation speed and ultra high modulation efficiency directly modulated two-electrode tapered laser diode is steered using a nematic phase-only Liquid-Crystal On Silicon Spatial Light Modulator (LCOS SLM) by displaying reconfigurable 256 phase level gratings. [ABSTRACT FROM PUBLISHER]

A reconfigurable mode demultiplexer based around a liquid crystal spatial light modulator is demonstrated to optically demultiplex modes that share a propagation constant as separate modal channels using a single shared phase mask per polarization for all channels. [ABSTRACT FROM PUBLISHER]

Optical tweezers use focused laser light to manipulate microscopic particles. We discuss the underlying physics of the technique in terms of a gradient force exerted by the light on the particles. The versatility of optical tweezers is highlighted, in particular, we explain how spatial light modulators and various imaging methods have greatly enhanced their range of applications. [ABSTRACT FROM AUTHOR]

In this paper, we report on the heterogeneous integration of monocrystalline silicon membranes for the fabrication of large segmented micromirror arrays for adaptive optics applications. The design relies on a one-level architecture with mirrors and suspension formed within the same material, employing a large actuator gap height of up to 5.1 \mu\m to allow for a piston-type mirror deflection of up to 1600 nm. Choosing monocrystalline silicon as actuator and mirror material, we demonstrate a completely drift-free operation capability. Furthermore, we investigate stress effects that degrade the mirror topography, and we show that the stress originates from the donor silicon-on-insulator wafer. The novel heterogeneous integration strategy used in this work is capable of reducing this stress to a large extent. \hfill[2011-0303] [ABSTRACT FROM AUTHOR]

A spatial light modulator at the transmitter is used in conjunction with a standard multimode coupler at the receiver to modally multiplex 2 × 12.5 Gb/s nonreturn-to-zero channels using direct detection over 2 km of 940 MHz OM2 fiber without electronic processing. The wavelength dependence of this technique over a 4.5 THz band is also investigated. [ABSTRACT FROM PUBLISHER]

We analyze the performance of a spatial fiber switching system when using a pixelized mirror, such as a LCoS or MEMS spatial light modulator, in place of a large tilting micromirror. Our findings demonstrate the dependence of insertion losses on tilt angles or fiber counts, and the dependence of the crosstalk in the number of phase quantization levels and random phase errors. The former effects can be minimized by satisfying a relationship between the tilt angle to a fiber, the pitch of the array, and the optical wavelength. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a provably optimal technique for minimizing intersymbol interference (ISI) in multimode fiber (MMF) systems using adaptive optics via convex optimization. We use a spatial light modulator (SLM) to shape the spatial profile of light launched into an MMF. We derive an expression for the system impulse response in terms of the SLM reflectance and the field patterns of the MMF principal modes (PMs). Finding optimal SLM settings to minimize ISI, subject to physical constraints, is posed as an optimization problem. We observe that our problem can be cast as a second-order cone program, which is a convex optimization problem. Its global solution can, therefore, be found with minimal computational complexity, and can be implemented using fast, low-complexity adaptive algorithms. We include simulation results, which show that this technique opens up an eye pattern originally closed due to ISI. We also see that, contrary to what one might expect, the optimal SLM settings do not completely suppress higher order PMs. [ABSTRACT FROM PUBLISHER]

We report an experimental procedure for achieving spatial modulation of the phase of an input wave field with an off-the-shelf twisted nematic liquid crystal display. This method involves illumination of an addressed liquid crystal display (LCD) with circularly polarized light and measurement of the Stokes parameters of the outgoing beam as the applied voltage is changed. The analysis of the distribution of the polarization states in the S1-S2 plane suggests a simple way to optimize the liquid crystal phase response by means of a properly oriented quarter wave-plate followed by an analyzer. Laboratory results for a commercial display are presented. A phase modulation depth of 240deg is obtained at 514 nm with a residual intensity variation which is lower than 4% [ABSTRACT FROM PUBLISHER]

By employing an RF-photonic arbitrary waveform generator, the authors experimentally obtained complex high-power RF waveforms with spectra spanning more than a decade and voltage amplitudes of more than 13 V in a system limited by a gain ripple of up to 5 dB and phase distortion of over 200°. A spectral predistortion technique tailored to photonically assisted waveform generators that can overcome substantial RF amplifier gain ripple and phase distortion in order to generate high-power (> 30 dBm) ultrawideband arbitrary RF waveforms is presented. [ABSTRACT FROM PUBLISHER]

A free space adaptive optical interconnect is reported, in which an optically modulated channel from a vertical-cavity surface-emitting laser at 1.25 Gb/s is steered using reconfigurable binary phase gratings displayed on a ferroelectric liquid crystal on silicon (LCOS) spatial light modulator (SLM), to correct for misalignment. The optical system, and addressing scheme to maintain a transparent optical path, is described. The measured optical losses total 13.6 dB, sufficient to give a bit error rate (BER) of 10-12 with current optical transmitter and receiver technology. This is, to our knowledge, the first demonstration of a high-speed data transmission through an adaptive optical interconnect using an "off-the-shelf" commercial ferroelectric display panel. [ABSTRACT FROM PUBLISHER]

Polarization-insensitivity is achieved in a reflective spatial light modulator by laying a quarter-wave plate (QWP) at the incident wavelength directly over the mirror pixels of a silicon backplane, and forming a nematic Freedrickcz cell over the QWP to modulate the reflected phase. To achieve the highest drive voltage from the available silicon process, a switched voltage common front electrode design is described, with variable amplitude square wave drive to the pixels to maintain constant root-mean-square drive and minimize phase fluctuations during the dc balance refresh cycle. The silicon has been fabricated and liquid-crystal-on-silicon cells both with and without the QWP assembled; applications include optically transparent switches for optical networks, beam steering for add-drop multiplexers for wavelength-division-multiplexing telecommunications, television multicast, and holographic projection. [ABSTRACT FROM PUBLISHER]