Properties Of Spatial Light Modulator Research Articles

Calibration method to determine the complete Jones matrix of SLMs

We present a simple method to determine the polarimetric properties of spatial light modulators (SLMs) for each grey level by means of irradiance measurements. The Jones matrix of the SLM is obtained without any assumption about its properties, so it can be applied for more devices than previous works. This method is simple enough to be quickly performed, while offers better results than previous works, as it reduces the error in the prediction of transmission intensities in a factor between 5 and 380.

Measuring of nonlinear properties of spatial light modulator with different wavelengths

The non-linear optical properties of Spatial Light Modulator(SLM) represented by Nonlinear Refractive Index (NLR) and nonlinear Absorption coefficient has been measured in this work using highly sensitive method known as Z-scan technique for different wavelengths (red and green). The capability to do instant measurements of different nonlinear optical parameters lead to consider these techniques as a one of the most desired and effective methods that could apply for different materials. The results showed that the NLR were in the same power for the different wavelengths while the nonlinear absorption is higher in case of green laser.

Scalable digital spatial light modulator-micromesh heterostructures for real time wave optical applications.

For large-scale real time wave optical applications, we propose and demonstrate scalable simple digital spatial light modulator (SLM)-micromesh (μM) heterostructures, which fully harness ubiquitous well developed consumer information displays for real time large-scale SLMs and advanced patterning technologies for promoting the wave optical properties of SLMs of any size. Weakly diffractive projection mode large-scale SLMs with poor demultiplexity are transformed to highly diffractive mode heterostructures with fine patterned micromeshes as efficient demultiplexers or wave optical promoters. As a result, diffraction efficiency, diffraction angle, demultiplexity, multiplexity, reconstructed image quality and numbers of visibly reconstructed images largely increase even though the pixel pitches of the employed SLMs are many orders of magnitude larger than the wavelength of the illuminating light. The approach shown in this study can be applicable even for any sized weakly diffractive SLMs, and can simultaneously increase the effective spatial bandwidth and the physical dimension required for their wave optical applications. This can't be achieved by presently available SLMs alone.

Shearing interferometer based on the birefringent properties of a spatial light modulator

We present a shearing interferometer that is based on the birefringent properties of a phase-only spatial light modulator. The main advantages of this approach are the high flexibility, the robustness, and the light efficiency. In contrast to already existing methods the suppression of unwanted diffraction orders is not required.

Fundamental properties of spatial light modulators for the approximate optical computation of Fourier transforms: a review

The performance of optical computers that include program- mable Fourier optics depends intimately both on the physical character- istics of the particular spatial light modulator (SLM) and on the particular algorithms that map the ideal signal into the available modulation range of the SLM. Since practical affordable SLMs represent only a limited range of values in the complex plane (e.g., phase-only or quantized phase), numerous approaches have been reported to represent, ap- proximate, encode or map complex values onto the available SLM states. The best approach depends on the space-bandwidth product (SBWP) of the signal, number of SLM pixels, computation time of encod- ing, the required response time of the application, and the resulting per- formance of the optical computer. My review of various methods, as applied to most current SLMs, which have a relatively low number of high cost pixels, leads me to recommend encoding algorithms that address the entire usable frequency plane and that emphasize the fidelity of the approximated Fourier transform over maximization of diffraction effi- ciency and minimization of approximation error. Frequency-dependent diffraction efficiency (due to pixel fill factor of discrete SLMs or resolution of spatially continuous SLMs) is also evaluated as a factor that can limit usable SBWP and possibly modify the choice of encoding method. © 2001 Society of Photo-Optical Instrumentation Engineers. (DOI: 10.1117/1.1409336) Subject terms: spatial light modulators, computer generated holography, complex-valued encoding, statistical optics.

Coherent optical characterization of magnetooptical spatial light modulators

A precision optical system, developed for characterizing the amplitude and phase properties of spatial light modulators, was used to characterize a 48 x 48 pixel magnetooptic spatial light modulator (MOSLM). Considerable variations in the amplitude (+/-25%) and phase transmittance (+/-50%) over the area of a given pixel were observed with coherent light illumination. The pixel-to-pixel variations in the average amplitude (+/-5%) and average phase (+/-6%) were considerably less. The contrast ratio and the polarization rotation for full frame monochromatic illumination were ~10:1 and 11.25 degrees , respectively. For illumination within a single pixel, the contrast ratio and polarization rotation were ~100:1 and 14.0 degrees , respectively. A theoretical model is presented showing that the reduced values for full frame illumination may be described by the coherent addition of light of unrotated polarization (transmitted between pixels and around the edges) with the polarization rotated light. The amplitude and phase characteristics of the MOSLM were found to be a very stable with repeated switching of the pixel and with switching of neighboring pixels. This stability is a central requirement in coherent optical information processing.

Bistable properties of spatial light modulator with internal feedback

A bistable spatial optical device has been developed on the basis of a spatial light modulator which contains photosensitive and electrooptical liquid crystal layers, where an internal feedback loop is established.