Novel design approach achieves nonlinear photochromism using easy-to-synthesize rhodamine spirolactam derivatives

https://phys.org/news/2024-05-approach-nonlinear-photochromism-easy-rhodamine.html

"Photochromic compounds, photo switches changing color when exposed to light... nonlinearity enhances contrast, spatial resolution...nonlinear photochromism induced with low-intensity light using triplet–triplet annihilation,with triplet sensitizer, annihilator, photochromic compound all provided in single molecule: Rhodamine spirolactams... Rh–Pe color change efficiency increases with higher-intensity light... high-resolution photolithography, 3D printing, high-density optical disks"