Implementation of a compact optical architecture for visual psychophysical tests based on spatial light modulators

Spatial light modulators (SLM) are increasingly used as active optical elements for wavefront manipulation in holography, adaptive optics, and beam shaping. In this work, we present the implementation and test of a compact optical system based on a computer-controlled SLM to perform psychophysical tests on visual acuity and contrast sensitivity. The Fourier transform of the desired pattern, e.g., Snellen optotype or Gabor grating, is encoded and uploaded on the SLM and customized in terms of final size, contrast, orientation, and position. The device is controlled with specific software in order to conduct psychophysical tests and converge quickly towards a threshold estimate. Thanks to its versatility and scalability, the platform can be extended straightforwardly to any visual test, and a preliminary study on the effect of stochastic resonance on contrast sensitivity threshold is here shown and discussed.