Abstract-Tunable Antenna-Coupled Intersubband Terahertz (TACIT) Mixers: The Quantum Limit Without the Quantum Liquid

M. S. Sherwin, C. Cates, B. Serapiglia, Y. Dora, J. B. Williams, K. Maranowski, A. C. Gossard, W. R. McGrath

https://arxiv.org/abs/1909.10664

At present, nearly quantum-limited heterodyne receivers for Terahertz (THz) frequencies require cooling to temperatures below 4K. We are working to build semiconductor-based "tunable antenna-coupled intersubband terahertz" (TACIT) heterodyne mixers for 1-5 THz. We predict that they can achieve single-sideband noise temperatures of a few hundred K with intermediate frequency (IF) bandwidth >10 GHz, while operating at lattice temperatures >20 K and requiring local oscillator (LO) power ~ 1 μW.

Abstract-Continuous-wave 1550 nm operated terahertz system using ErAs:In(Al)GaAs photo-conductors with 52 dB dynamic range at 1 THz

A.D.J. Fernandez Olvera, H. Lu, A. C. Gossard, and S. Preu

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-23-29492

Telecom-wavelength compatible photoconductors benefit strongly from the large amount and affordability of telecom lasers and components but there are demanding requirements on material development. We demonstrate continuous-wave (CW) photomixing with a setup that only uses ErAs:In(Al)GaAs devices with a peak dynamic range (DNR) of 78 dB and a bandwidth of ∼3.65 THz at an integration time of 300 ms and only 26 mW laser power on each device. The ErAs:InGaAs receiver further features a factor of two lower noise equivalent power (NEP) than a state-of-the-art photoconductor, despite an antenna mismatch.

© 2017 Optical Society of America under the terms of the OSA Open Access Publishing 

Abstract-Arrayed free space continuous-wave terahertz photomixers

 

 

S. T. Bauerschmidt, G. H. Döhler, H. Lu, A. C. Gossard, S. Malzer, and S. Preu »View Author Affiliations
http://www.opticsinfobase.org/ol/abstract.cfm?URI=ol-38-18-3673
We present free space coherent arrays of continuous-wave terahertz (THz) photomixers and compare the results to on-chip arrays. By altering the relative phases of the exciting laser signals, the relative THz phase between the array elements can be tuned, allowing for beam steering. In addition, the constructive interference of the emission of  N elements leads to an increase of the focal intensity by a factor of  N² while reducing the beam width by ~ N −¹ below the diffraction limit of a single source. Such array architectures strongly improve the THz power distribution for stand-off spectroscopy and imaging systems while providing a huge bandwidth at the same time. We demonstrate this by beam profiles generated by a  2 x 2 and a  4  x 1 array for a transmission distance of 4.2 m. Spectra between 70 GHz and 1.1 THz have been recorded with these arrays.