Device based on surface acoustic waves to monitor an active THz diffraction grating based on VO2

Abstract

We develop new method to locally monitor the resistance and temperature in phase-change VO2 based metamaterials. The method is based on the use of surface acoustic waves (SAWs) generated in the LiNbO3 substrate. Surface acoustic waves are generated in N acoustic channels of the device using a single broadband RF signal with N frequency channels. The method opens up new possibilities for monitoring the states of an active THz metasurface, including detection of aging, technological defects, and crosstalk within its elements.
Information on induced SAW attenuations in acoustic channels which coincide with VO2 gratings lines is contained in a single RF response with N independent frequency channels. As a result, resistance changes in all grooves of the VO2-based diffraction grating are monitored in advance even before the arrival of THz radiation. Scenarios for programming and monitoring several types of active THz diffraction gratings are modeled: reflective binary amplitude with adjustable period and gradient amplitude grating. The obtained calculations helped to identify the limitations that should be taken into account about the length of the acoustic channel when designing the active part of the THz grating.
Research was funded by Russian Science Foundation, grant № 24-29-00175 at SFU.

Speaker

Ochkurov Maxim
Laboratory of Nanomaterials,SFU
Russia

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