Hyperspectral two-dimensional visual stimulator.

Abstract

We built a hyperspectral two-dimensional visual stimulator (H2DVS) with two diffractive gratings and a digital micro mirror device (DMD). White light from a Xenon arc lamp was collimated and reached to the first diffraction grating. The light was separated into each spectrum and focused onto the DMD. The spectral components were arbitrarily chosen by controlling the DMD, and went to two off-axis lenses and to the second diffraction grating to form a one-dimensional pixel array. Using a galvanic mirror to scan the array, we eventually obtained a 20-x-28-mm hyperspectral image with 100-x-10 pixels and 64 intensity levels. Measuring the maximum luminance at nine different points in the image, the average and standard deviation was 45.53 ± 1.21 cd/m2. The spectral resolution was about 1 nm. We confirmed that the color space was almost fully covered. We expect the H2DVS will be a versatile device for color-matching experiments with exact wavelengths. It may also be useful for performing any psychophysical experiments which require precise spectrum. One example is a visual acuity test in particular wavelengths. Another example is an experiment with iridescence that is related to optical interference. As our preliminary study, we simulated an anomaloscope. We obtained the similar results with the H2DVS for the dichromats and anomalous trichromats to those obtained with a conventional anomaloscope. As we can use any virtual multiple light sources with this simulated anomaloscope, it may be possible to investigate not only M and L cones but S cone, rod, and even melanopsin receptor.

Meeting abstract presented at OSA Fall Vision 2012