2019/07/30 by J. Žmuidzinas, Zmuidzinas, J., Boris S. Karasik +5
Engineering · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Physics of Superconductivity and Magnetism #Superconducting and THz Device Technology #Terahertz technology and applications
paper · pdf · doi:10.48550/arxiv.1907.13198
openalex publication_date 2019/07/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In their article, Wang et al. [1] report a new scheme for THz heterodyne detection using a laser-driven LTG-GaAs photomixer [2, 3] and make the impressive claim of achieving near quantum-limited sensitivity at room temperature. Unfortunately, their experimental methodology is incorrect, and furthermore the paper provides no information on the mixer conversion loss, an important quantity that could readily have been measured and reported as a consistency check. The paper thus offers no reliable experimental evidence that substantiates the claimed sensitivities. To the contrary, the very high value reported for their photomixer impedance strongly suggests that the conversion loss is quite poor and that the actual sensitivity is far worse than claimed.