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We report room temperature terahertz detection in hBN/graphene/hBN heterostructures. The obtained record combination of high-speed (response time < 1 ns) and high sensitivity (noise equivalent power ~ 100 pWHz-1/2) is enabled by the photo-thermoelectric effect.

In this study, simulations and measurements were used to investigate stray light properties of the three-mirror off-axis telescope of a new satellite for atmospheric research called Mesospheric Airglow/Aerosol Tomography Spectroscopy (MATS). A 700 mm breadboard baffle for stray light rejection has been designed and tested. Good performance was achieved by coating the baffle’s inside with Vantablack S-VIS R , which has a hemispherical reflectance of 0.2-0.6% across the instrument’s detection band (270-776 nm). A point source transmittance (PST) down to 10−6 was measured for the full-size baffle breadboard. This is in excellent agreement with simulations performed in OpticStudio/LightTools, where scattering was modeled using empirical BRDF data. From the breadboard results, a simulation model of a flight-representative prototype model of the entire instrument was set up in OpticStudio. Strong signals just outside the field of view constitute the biggest challenge, where a PST in the order of 10-6 − 10-4 is required. Simulations suggest that the PST of the prototype limb instrument will be lower than this. Adding to these simulations, an instrument model was developed, which will be utilized by the end-users to remove unwanted features in the data stemming from the instrument itself. Besides stray light, the model also takes into account the most relevant aspects of the instrument, such as image resolution (from measured/simulated point spread functions), image sensor characteristics as well as temperature and wavelength dependencies.

We present a 220 GHz imaging radar prototype that has been developed in the European Defense Agency (EDA) project TIPPSI. The purpose of the development was to demonstrate short-range high-resolution 3D imaging for security applications at checkpoints, and to guide the development of stand-off real-time millimeter wave and sub-millimeter wave imaging systems for detection of larger objects at greater distances. An additional goal was to experimentally verify simulation techniques for active (sub)-mmw imaging systems, the verified simulation techniques can then be used to explore different system architectures. The 220 GHz imaging radar prototype consist of a flexible, mechanically scanned optical system that can support linear arrays of transmit/receive (TxRx) units up to 150 mm in length. The optical system is divided into two parts: A compact Dragonian system including the mechanical scanner that can be used as a stand-alone imager at reduced target distance and resolution, and a confocal system that can be added to achieve the full resolution of 1 cm x 1 cm x 1 cm at 4.5 m target distance. The field of view of the full resolution system is 70 cm x 70 cm. The front-end is currently populated by 4 TxRx units that are sparsely distributed along the 150 mm focal plane. The TxRx units operate in frequency modulated continuous wave (FMCW) mode and have a bandwidth of 24 GHz. Each TxRx unit use a single horn antenna and the transmit- and receive signals are generated and received using the same circuits which avoids the need of a duplexer. We will demonstrate high resolution 3D videos taken at 1 Hz frame rate and compare the individual images with simulations using electromagnetic simulators and character/clothes animation.

More efficient continuous-wave photonic nearinfrared mixers as terahertz sources are investigated with the motivation to develop a universal photonic local oscillator for astronomical submillimeter/terahertz receiver systems. For this, our group has developed new concepts for vertically illuminated traveling-wave (TW) photomixers. The new device called TWUni- Travelling Carrier photodiodes (TW-UTC PD) was simulated, modeled and shall be optical/terahertz tested at the Electrical Engineering Department of the University of Chile, whereas device fabrication is performed at the MC2 cleanroom facility at Chalmers University of technology. We are reporting on first progresses in this direction.

The development of a 210 GHz radar system intended to study security applications such as personnel scanning is reported. The system is designed to operate with a transmit antenna floodlighting the target scene and a mechanically scanned antenna-integrated receiver module. For increased performance and potential future volume production the receiver front-end is based on highly integrated MMICs manufactured using the IAF 0.1 µm GaAs mHEMT process made available through a Swedish-German MoU. A single-chip MMIC solution is being developed containing feed antenna, LNA, mixer and an LO multiplier-chain. The transmitter part is based on a high-power HBV quintupler source-module.

We present a high-power frequency tripler for 110 GHz and a quintupler for 200-210 GHz. The tripler (×3), that is based on a single HBV diode, produces 240 mW of output power with a 3-dB bandwidth of 6%. This is the highest output power ever recorded for an HBV based multiplier irrespective of output frequency. The module features an ultra-compact waveguide block design, and a microstrip matching circuit on high-thermal-conductivity AlN to improve the power handling capability. Furthermore, we present an HBV quintupler (×5) that delivers more than 20 mW at 202 GHz.