We report on the role of ferroelectricity on the physical and electro-optic parameters in suspensions of nanoparticles in cyclohexane based, fluorinated nematic liquid crystals. The dielectric and elastic constants, response time, and viscosity of the suspensions were analyzed experimentally and compared with the undoped samples. Our study shows a decrease in the splay elastic constant and an increase in the dielectric constants, together with an increase in the average rotational viscosity.

We present a two-quantum well THz intersubband laser operating up to 192 K. The structure has been optimized using non-equilibrium Green's function model. The result of this optimization was confirmed experimentally by growing, processing, and measuring a number of proposed designs. At high temperature (T > 200 K), the simulations indicate that lasing fails due to a combination of electron-electron scattering, thermal backfilling, and, most importantly, re-absorption coming from broadened states.

There is a need for low-cost and easily accessible optical devices for THz applications. THz devices can be manufactured rapidly with 3D printing while using THz transparent materials. In this work, we optimized the parameters for high-resolution 3D printing of a THz transparent filament, cyclic olefin copolymer (TOPAS), in order to 3D print high quality pipe THz waveguides. We used nozzles with diameters between 0.15 mm and 0.80 mm in a wide range of temperatures and speeds. We show that for high quality TOPAS 3D printing, the most important parameters are the bed and the printing temperature. The optimized 3D printing parameters for the nozzle diameter 0.15 mm were used for THz pipe waveguides with diameters in the range of 5-9 mm and cladding thickness of 0.3-0.8 mm. Transmission measurements corroborated the results predicted by simulations for core mode frequencies in the range of 250-900 GHz.

We report a monolithic THz planar Fabry–Perot cavity fabricated with wafer bonding and provided with metallic mirrors with subwavelength apertures. We demonstrate its coupling to the cyclotron resonance of a high-mobility, two-dimensional electron gas. Q factors up to 89 are observed for the first mode at ≃300 GHz, with cooperativity C = 56.4 and a normalized coupling ratio in the first mode of up to 17.5% and the third mode of up to 6.4%.