Photochromism into optics: Opportunities to develop light-triggered optical elements

Opportunities to apply photochromism in smart optics are highlighted. The reversible light-triggered switching in UV–vis absorption and in the refractive index can be exploited to develop rewritable optical elements, specifically tunable masks, amplitude holograms and volume gratings. Description of the configuration and performance of the optical devices with possible open issues is preceded by a discussion dealing with the molecular features that provide a strong modulation of the material properties which is required for a convenient functioning of the device.

► Photochromic materials as active layer for smart optics.
► Both fundamental issues regarding molecular design and material optimization have to meet technological requirements.
► UV–vis transmittance contrast enables development of rewritable masks and amplitude holograms.
► Modulation of the refractive index enables development of phase holographic elements.