Photo-Thermally Induced Current Switching in Vanadium-Dioxide-Based Devices Using CO2 Laser Pumping.

By utilizing a CO2 laser as an illumination light source for triggering, we demonstrated bidirectional laser triggering in a two-terminal planar device based on a highly resistive vanadium dioxide (VO2) thin film. Bidirectional laser triggering between 0 and 10 mA was realized by switching the CO2 laser whose focused beam illuminated the VO2 film, and transient responses of laser-triggered devices were investigated when periodical laser pulses excited the VO2-based device at a variety of pulse widths and repetition rates. A switching contrast between off- and on-state currents was evaluated as -3333, and the rising and falling times were measured as -39 and -21 ms in the transient responses obtained by using periodic laser pulses with a pulse width of 100 ms, respectively.