Abstract-Electrical control of terahertz frequency conversion from time-varying surfaces

Kanghee Lee, Jagang Park, Jaehyeon Son, Bong Joo Kang, Won Tae Kim, Seong Cheol Lee, Bumki Min,  Fabian Rotermund,

Fig. 1 Experimental information. (a) Schematic of experimental setup. (b) Spectrum of single-cycle THz waves generated from LiNbO3 crystal with waveform in time domain (inset). (c) Spectrum of multi-cycle THz waves modulated through stacked band-pass filters with waveform in time domain (inset).

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-9-12762

We investigate the electrical control of frequency conversion from a time-varying interdigitated photo-conductive antenna (IPCA) and time-varying metasurface in the terahertz (THz) frequency range. Ultrafast near-infrared (NIR) optical pulses rapidly modify the conductivities of the IPCA and metasurface; however, external voltages can retard this conductivity transition. Thus, external voltages can be used to control the frequency conversion process based on the interaction between the THz waves and the time-varying surfaces. In the IPCA, both frequency up- and down-conversion processes are suppressed by external voltages. However, in the metasurface, the down-conversion is dramatically suppressed by external voltages, whereas the suppression on the up-conversion is less effective.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement