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.

Programmable multiwavelength modelocked laser

Abstract: A programmable multiwavelength modelocked laser system. Embodiments of the system can use a computer, gratings, optical spectrum analyzer and SLM(spatial light modulator) inside of a laser cavity to control output amplitudes and phase of each of the wavelength channels of a multiple wavelength laser system. The programmable control allows for wavelength intensity(amplitude) levels of up to approximately 16 channels to be controlled and evened out. An InGaAsP SOA based modelocked multiwavelength ring laser is stabilized using a programmable liquid crystal spatial light modulator in a feedback control loop. The system produces 16 independent modelocked RZ wavelength channels at 10 GHz with 0.44 dB flatness and 25 psec pulses.

Content-adaptive high-resolution hyperspectral video acquisition with a hybrid camera system

Abstract: We present a hybrid camera system that combines optical designs with computational processing to achieve content-adaptive high-resolution hyperspectral video acquisition. In particular, we record two video streams: one high-spatial resolution RGB video and one low-spatial resolution hyperspectral video in which the recorded points are dynamically selected using a spatial light modulator (SLM). Then through video-frame registration and a spatio-temporal spreading of the co-located spectral/RGB information, video with high spatial and spectral resolution is produced. The sampling patterns on the SLM are generated on-the-fly according to the scene content, which fully exploits the self-adaptivity of the hybrid camera system. With an experimental prototype, we demonstrate significantly improved accuracy and efficiency as compared to the state-of-the-art.

Optically controlled phased array radar

Abstract: A compact, stable, and optically efficient two dimensional spatial light modulator-based electro-optical control system for large (>1000 elements) phase-based phased array antennas uses two externally phase-locked lasers to generate respective pluralities of first and second light beams that are respectively mutually orthogonally polarized. Respective ones of the first and second light beams are combined to pass along collinear and coincident paths to form a plurality of combined light beams. The frequency difference between the first and second light beams which form the constituent beams in each combined beam cause an interference pattern that, upon heterodyne detection of the optical signal and conversion to an electrical antenna drive signal, provides control of the carrier frequency for driving the antenna. A phase delay is introduced via electrical control of an array of birefringent-mode nematic liquid crystal pixels that selectively phase delay one of the constituent light beams having a predetermined linear polarization in each combined light beam, while the other constituent beam is not phase delayed and is used as a reference for microwave/millimeter wave signal generation via interferometric detection through a photodiode. Further, a frequency shift unit coupled to the laser assembly enable an intermediate frequency offset to be selectively introduced, such as during receive cycles of the radar, such that electrical output signals generated by the optical signal processing system exhibit a desired intermediate frequency.

Generation and nonlinear self-trapping of optical propelling beams

Abstract: We generate optical beams with rotating intensity blades by employing the moire technique. We show that the number of the blades and the speed and direction of rotation can be controlled at ease with a spatial light modulator, while no mechanical movement or phase-sensitive interference is involved. By applying a noninstantaneous self-focusing nonlinearity, we demonstrate both theoretically and experimentally self-trapping of such optical propelling beams.

Spatial light modulator and projector

Abstract: Exemplary embodiments of the invention provide a spatial light modulator that is inexpensive, has a long life and a high light use efficiency, and with which can be obtained a high-contrast image, and a projector disposed with the spatial light modulator. Exemplary embodiments provide a spatial light modulator including a liquid crystal layer that includes plural aperture regions AP, modulates light in accordance with image signals and emits the modulated light; and microlens elements that are disposed at an incident side of the liquid crystal layer in correspondence to the aperture regions AP and condense the light made incident so that the light passes through the aperture regions AP. The microlens elements include plural focal positions f1 and f2 that are different per plural substantially annular portions R1 and R2 around an optical axis AX.