Optical induction and detection of fast phase transition in VO 2

Abstract

We have optically induced the Insulator to Metal Phase transition in VO 2 sputtered films within 20 nsec by using a Q-switched ruby laser. The phase transition was detected by monitoring a He-Ne probe beam reflected off the film surface. It is shown that this fast phase transition is induced by photon → electron → phonon energy transfer process. We also discuss the possibility of using similar measurements to deduce the physical origin of the transition.