Synthetic holograms based on photochromic diarylethenes

Abstract

Diarylethenes are P-type photochromic systems showing reversible light-induced modulation of optical properties, e.g., transmittance and refractive index, in the visible and near infrared regions. Transmittance can be progressively tuned according to the illumination dose, and the pattern written and erased several times with light. We demonstrated binary Computer Generated Holograms based on of photochromic materials, to be used as adaptable reference surfaces in interferometric tests. We encoded by Direct Laser Writing binary amplitude Fresnel Zone Plates into photochromic substrates and successfully tested them into an interferometric setup. More recently, we exploited the non-threshold behavior of photochromic materials to encode grayscale CGHs, which give a better wavefront reconstruction than binary holograms. We propose to use a device based on a Digital Micro-mirror Device as a real-time reconfigurable mask. We recorded for the first time amplitude grayscale CGHs and reconstructed them with high fidelity in shape, intensity and size.