Enhanced photo-assisted electrical gating in vanadium dioxide based on saturation-induced gain modulation of erbium-doped fiber amplifier

Abstract

By incorporating saturation-induced gain modulation of an erbium-doped fiber amplifier (EDFA), we have demonstrated a high-speed photo-assisted electrical gating with considerably enhanced switching characteristics in a two-terminal device fabricated by using vanadium dioxide thin film. The gating operation was performed by illuminating the output light of the EDFA, whose transient gain was modulated by adjusting the chopping frequency of the input light down to 1 kHz, onto the device. In the proposed gating scheme, gated signals with a temporal duration of approximately 40 micros were successively generated at a repetition rate of 1 kHz.

Bidirectional laser triggering of planar device based on vanadium dioxide thin film

“…When a VO 2 thin film forms a two-terminal device, electric field applied to the device can cause this PT [4], and a negative differential resistance (NDR) [5,7], originated from the discontinuity of the PT, is observed in the VO 2 -based device, resulting in not an exponential increase but an abrupt jump of electrical current. In particular, through the interaction with external light illuminating the VO 2 device, this highly nonlinear current-voltage (I-V) behavior can be modulated temporarily [8,9] or permanently [10]. By incorporating this photo-induced modulation of the I-V behavior of the device, field-induced electrical oscillation in VO 2 can be generated or extinguished, and its frequency can be externally controlled [11].…”

“…In addition, bistable electrical switching, i.e., bistable device resistances, can also be realized at a single illumination (probe) power [12,13]. In our previous studies, photo-assisted electrical gating was implemented in a two-terminal planar VO 2 device, and its threshold voltage, after which a current jump occurred triggering the PT of VO 2 , could be shifted by controlling the optical power of the infrared laser illuminating the device [6,8,9]. However, the maximum on-state current of the device was at most ~3.9 mA resulting in an amplitude switching ratio between on-and off-state currents of less than 4 [6].…”

“…In particular, the relationship between the maximum on-state current and the bias voltage applied to the device has not been clarified. It was restrictive to control the temporal duration of the on-state current, during which the laser illuminated the device [8,9]. For VO 2 devices to be considered for the practical application of optically-gated switches like light-triggered thyristors, lots of device parameters including the switching ratio, the off-state current, and the on-state current should be significantly improved, and the duration of the switched state should be flexibly chosen.…”

Bidirectional laser triggering in highly-resistive vanadium-dioxide thin films by using a 966-nm pump laser diode

“…When a VO 2 thin film is used to form a two-terminal device, the electric field applied to the VO 2 -based device can also cause this PT [4], and a negative differential resistance [5,7], which * E-mail: yongwook@pknu.ac.kr; Fax: +82-51-629-6323 is responsible for the discontinuity of the PT, is observed in the device, resulting in an abrupt jump in the electrical current. In particular, through the interaction of VO 2 with light, this strongly nonlinear current-voltage (I-V ) behavior can be altered temporarily [8,9] or permanently [10].…”

“…Photo-assisted electrical gating was reported in a twoterminal planar VO 2 device, and its threshold voltage, after which an abrupt jump in the current occurred triggering the PT of VO 2 , could be changed by adjusting the illumination power of the infrared laser [6,8,9]. With the incorporation of this photo-induced modulation of the electrical property of the device, an electric-field-induced oscillation in VO 2 can be created or extinguished, and the oscillation frequency can be regulated [11].…”