Measurement and compensation of optical aberrations using a single spatial light modulator

Abstract

We describe a compact adaptive optical system using a spatial light modulator (SLM) as a single element to both measure and compensate optical aberrations. We used a low-cost, off-the-shelf twisted nematic liquid-crystal display (TNLCD) optimally configured to achieve maximum phase modulation with near constant transmittance. The TNLCD acts both as the microlens array of a Hartmann-Shack wavefront sensor and as the aberration compensation element. This adaptive setup is easy to implement and offers great versatility.

Complete Modal Representation with Discrete Zernike Polynomials - Critical Sampling in Non Redundant Grids

“…Regarding practical applications, sampling grids with inhomogeneous densities, such as quadratic spiral, or random (irregular) are difficult to implement in conventional monolithic microlens arrays used in Hartmann-Shack sensors, segmented mirrors, etc. However there are highly flexible and re-configurable (almost in real time) devices such as liquid crystal spatial light modulators (Arines et al 2007) or laser ray-tracing methods (Navarro & Moreno-Barriuso, 1999) which can easily implement almost any possible sampling grid.…”

Controlled Multibeam Supercontinuum Generation With a Spatial Light Modulator

“…The use of SLMs has benefited a wide range of applications in adaptive optics [20,21], scattering media [22] or optical microscopy [23]. In this Letter, we report active control of MF in a solid medium by codifying a diffractive microlens array in a phase-only SLM.…”

Closed-loop adaptive optics with a single element for wavefront sensing and correction

“…If we extend the encoding scheme to eight levels, the maximum phase slope is reduced by one half but the light efficiency increases to 72%, and so on. In spite of this trade-off, the continuous improvement of the pixel pitch and fill factor of LCoS modulators (driven by the needs of the microdisplay industry) ensures results clearly superior to those presented in [6,11].…”

“…To this end, the measurement and compensation processes should be temporally or spatially multiplexed. In the temporal approach, compensation patterns and MLAs are alternately implemented onto the SLM, so in one step the device is used for wavefront sensing, whereas in the next step it is converted into the compensating unit [11]. This possibility enables it to make an optimum use of the light energy and the spatial resolution of the SLM.…”