Femtosecond two-photon-absorption-resonant four-wave mixing for time-resolved studies of photochromism in three dimensions

✍ Scribed by S.O Konorov; D.A Sidorov-Biryukov; I Bugar; D Chorvat Jr.; D Chorvat; A.M Zheltikov

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 309 KB
• Volume: 378
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/s0009-2614(03)01313-7

✦ Synopsis

Four-wave mixing (FWM) with two-photon absorption (TPA) resonances is shown to allow time-resolved studies of ultrafast processes involved in photochromism in three-dimensional spiropyran/PMMA samples on the femtosecond time scale. An FWM signal was produced using 130-fs pulses of 800-nm Ti:sapphire-laser radiation as a TPA-resonant pump and frequency-tunable pulses of an optical parametric amplifier as a time-delayed probe. Two-photon resonances allow strong one-photon absorption to be avoided, giving an access to any point inside a 3D photochromic sample. An ultrafast dynamics of photochromic transformations is revealed by comparing the time-resolved FWM signal with the cross-correlation of pump and probe pulses.