Abstract：Based on the multi-bands metallic split-ring resonator, the terahertz (THz) wave modulator which has been designed and modulated by optical and thermal control with the application of the photosensitive properties of GaAs material and the thermal induced phase transition properties of VO2 films. In addition, the influence of pump laser fluence and film temperature on the THz wave modulation characteristics has also been studied. The results show that multi-resonances frequency presents blue shift and the resonance strength decreases with the increasing of the pump laser fluence. Moreover, the frequency in the second resonance point (0.52 THz) is blue shifted by 0.14 THz and transmission amplitude increases at 50% for the pump laser fluence of 0.2 μJ·cm-2. Furthermore, the transmission amplitude of the THz wave decreases sharply when the temperature is over the VO2 phase transition temperature, and the transmission amplitude at the peak of the transmission spectrum of 0.63 THz decreases 45.5%. Finally, for the case of controlling by pump laser and temperature simultaneously, the resonance frequency also blue shifts and the transmission amplitude of the THz wave at the resonance point increases with the increasing of the pump laser fluence and film temperature. However, the film temperature plays a main role when it is over the VO2 phase transition temperature. The THz wave can be modulated obviously based on the designed THz wave modulator by controlling the light fluence and the film temperature, which can provide useful reference for the design and application of multi-functional THz wave function devices.
Key words：Terahertz; Multi-bands; Multi-control; Optical control; Thermal control
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