Ultrafast insulator-to-metal phase transition as a switch to measure the spectrogram of a supercontinuum light pulse

作者：Cilento Federico^*; Giannetti Claudio; Ferrini Gabriele; Dal Conte Stefano; Sala Tommaso; Coslovich Giacomo; Rini Matteo; Cavalleri Andrea; Parmigiani Fulvio

来源：Applied Physics Letters, 2010, 96(2): 021102.

DOI：10.1063/1.3291105

• high-speed optical techniques
• holey fibres
• metal-insulator transition
• optical properties
• photonic crystals
• solid-state phase transformations
• vanadium compounds

In this letter we demonstrate the possibility to determine the temporal and spectral structure (spectrogram) of a complex light pulse exploiting the ultrafast switching character of a nonthermal photoinduced phase transition. As a proof, we use a VO2 multifilm, undergoing an ultrafast insulator-to-metal phase transition when excited by femtosecond near-infrared laser pulses. The abrupt variation in the multifilm optical properties, over a broad infrared/visible frequency range, is exploited to determine, in situ and in a simple way, the spectrogram of a supercontinuum pulse produced by a photonic crystal fiber. The determination of the structure of the pulse is mandatory to develop pump-probe experiments with frequency resolution over a broad spectral range (700-1100 nm).

• 出版日期2010-1-11