Objectives: Due to the high free-space path loss at THz frequencies, moderate output powers and receiver sensitivities, future mobile THz applications such as THz communications but also mobile THz sensing for material identification (security, material science) must utilize meta-surfaces providing directive and steerable THz beams. The aim of this research is to investigate approaches for THz beam steering (Challenge II) and to integrate photonic phase shifters and wideband optical true-time-delays with mediated THz sources developed in the network (Challenge V) to demonstrate <1 THz beam steering. Expected Results: Optically mediated antennas array providing directive and steerable beams at up to 1THz Planned secondment(s): to FTMC (Dr. Irmantas Kašalynas), M10 for 1 month, on training in solid state THz sources and spectroscopic THz imaging to TRT (Dr. Daniel Dolfi), M16 for 1 month, for low-phase noise optical THz generation using TRTs dual-mode lasers to DAS (Dr. Valentin Polo), M28 for 2 months, for exp. testing of beam-steering arrays in spectroscopic imagers

Objectives: The purpose of this project is to develop arrays of photonic mediated THz sources to tackle the actual power limitations. Currently, the safe saturation current for THz photodiodes is below 10 mA allowing up to about a few 100 µW output power at 300 GHz. This research project will develop a novel 300 GHz multilayer waveguide technology for hybrid integration with a THz photodiode array. The aim is further to exploit HHI’s polymer board technology or SiN photonics for low-low power splitter as optical feeder and TRTs dual-mode laser for low-phase noise THz generation. This work addresses low-low THz waveguides and directive antennas (Challenge IV), high-power THz photodiode arrays as optically-mediated THz sources and photonic integration (Challenge I & V) and thus it will contribute to overcoming the challenges 1, 4 and 5. Expected Results: Low-phase noise, frequency stable and high-power optically-mediated THz sources for optical THz communications and as photonic LO for pumping mixers (e.g. SIS or low-barrier SD) in space and radioastronomy. Planned secondment(s): to ULIL (Prof. Guillaume Ducournau), M12 for 1 month, for round-robin characterization of THz photodiodes to HHI (Prof. Björn Globisch), M15 for 1.5 months, for designing the polymer-based low-loss optical power splitter to ACST (Dr. Oleg Cojocari), M 30 for 2 months, pumping ACSTs low-barrier SBD mixers with optical THz sources