Micrometer-scale photochromic recording on amorphous diarylethene film and nondestructive readout using near-field IR light

An amorphous photochromic recording film was prepared by spin coating a solution of a diarylethene derivative having bulky m-terphenyl groups. Near-field IR detection was carried out to read out the photochromic recording spots recorded by green laser irradiation on the film, and a spot with a diameter of approximately 5 ?m was nondestructively read out by the technique. The spot size was smaller than the wavelengths used for the read out, indicating the advantage of using the near-field technique.