Multi-states photochromic recording and nondestructive readout using IR light

ABSTRACT A photochromic polymer film containing three different kinds of diarylethene derivatives 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene ( 1 ), 1,2-bis(2,5-dimethyl-3-thienyl)-perfluorocyclopentene ( 2 ), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene ( 3 ) was prepared. Upon UV irradiation, these three derivatives changed to their closed-ring isomers having different colors, yellow, red, and blue. They showed different spectra not only in UV-vis. region but also in infrared (IR) spectral region. Upon irradiation with visible light of appropriate wavelengths, each closed-ring isomer was selectively bleached, and 3 bits 8 states recording was performed. The 8 states could be read out non-destructively by using IR light of appropriate wavenumbers. The technique will be applicable for near-field IR readout.