Electrically Controlled Terahertz Binary Coder Based on Hysteresis of Vanadium Dioxide Embedded Modulator

We experimentally demonstrated an electrically controlled terahertz (THz) binary coder based on hysteresis of vanadium dioxide (VO2) embedded modulator. The unit cell of the device consists of three horizontal metal lines and one vertical metal bar on a Si3N4-VO2-Si3N4-Si composite substrate. When no current is biased, the device has two resonant absorption dips locating at 0.55 and 1.0 THz, respectively. And the transmission of transparent band between two resonant absorption dips can be electrically modulated by the bias current. When the bias current increases to 0.3 A, the maximum modulation depth at 0.8 THz reaches 99%. This electrically tunability is resulted from the insulator-to-metal transition (IMT) of the embedded VO2 film. Most interestingly, a huge hysteresis is observed, which is important for developing electrically controlled THz binary coders. The high transmission state (I = 0 A) and low transmission state (I = 0.3 A) are defined as 1 and 0, respectively. And thus, the THz binary code of 1010 ... can be correspondingly obtained at 0.8 THz. The device can switch and encode the THz wave at selected frequency, which is very useful for THz communication and on-chip integrated THz system in the future.

Automated summary

An electrically controlled terahertz binary coder based on VO2 hysteresis was experimentally demonstrated, showing high modulation depth at 0.8 THz. The device utilizes insulator-to-metal transition of embedded VO2 film for electrical tunability, and can switch and encode THz waves at selected frequencies, making it promising for future THz communication applications.