High contrast optical switching in vanadium dioxide thin films

Thermochromic vanadium dioxide thin films prepared by radio-frequency sputtering exhibit controllable transmittance at 1550 nm with a dynamic range exceeding 103103. Efficient optical control with a laser beam at 532 nm is demonstrated with intensities as low as 3 W/cm2. Optical switch-on times as short as 100 μs are reported.