TUNABLE TERAHERTZ FILTERS BASED ON CARBON NANOTUBES

Subject of Research. The paper presents the study of optically tunable terahertz filter based on cross resonators coated with a layer of carbon nanotubes (CNT). We show experimentally control capability of the optical spectral characteristics of terahertz devices coated with a layer of single-wall carbon nanotubes. Method. The empirical formulas were used for calculation of the geometrical parameters of a cross-shaped resonator for a given resonant frequency and filter Q-factor. Experimental samples of the notch filter were made by laser engraving. A layer of carbon nanotubes, which were synthesized by aerosol chemical deposition, was deposited on an experimental filter sample. Experimental transmission spectra of an “empty” filter, a filter with a carbon nanotubes layer without pumping, and an optically pumped carbon nanotubes layer filter at a wavelength of 980 nm were measured by terahertz time-domain spectroscopy. Main Results. We have shown by experiments that optical pumping of a filter with carbon nanotubes layer leads to a decrease in the transmittance of the main resonance peak and a shift towards higher frequencies of the side resonance peak. Practical Relevance. Filters coated with carbon nanotubes layer can be used as inexpensive and compact tunable components for terahertz photonics devices.