The possibility to use an ultra-fast laser operating at 1550 nm wavelength to induce intensity self-modulation in metal-insulator phase transition VO2 thin films was investigated. The results show that a self-modulation value upto 0.55 can be obtained by using z-scan method. In comparison, an externally triggered phase transition induced by heating the sample produced a modulation depth of 0.995 corresponding to almost complete light absorption. The results suggest that significant self-modulation can be produced by fs laser pulses, but the modulation strength is partially suppressed by incomplete transition from a transparent to an absorbing state and potentially time delay in the rise of absorbance.
Hiltunen, J., Puustinen, J., Sitomaniemi, A., Pearce, S., Charlton, M., & Lappalainen, J. (2013). Self-modulation of ultra-fast laser pulses with 1550 nm central wavelength in VO2 thin films. Applied Physics Letters, 102(12), . https://doi.org/10.1063/1.4798831