Improvement of a Terahertz Detector Performance Using the Terajet Effect in a Mesoscale Dielectric Cube: Proof of Concept

[EN] Herein, a simple terahertz (THz) receiver that uses subwavelength focusing of the THz beam on the detector area is proposed. As a proof of concept, a THz detection system with an original optical coupling scheme is implemented, where the signal to be detected is coupled to a THz detector through a mesoscale dielectric particle lens. Coherent detection is successfully demonstrated with an enhancement of the detector sensitivity of about 4.3 dB, compared with that of a direct detection system with the slight decreasing (approximate to 1.67 times) of noise equivalent power value. The results show that the proposed method can reduce the size and increase the sensitivity of various THz systems, including imaging, sensing, and ranging, which would enable significant progress in different fields such as physics, medicine, biology, astronomy, security, etc.
This work was partially conducted within the framework of the Tomsk Polytechnic University Competitiveness Enhancement Program. This research was supported by the Agencia Estatal de Investigacion (grants TEC2015-65477-R, TEC2016-78028-C3-3-P, and RTI2018-097180-B-100), the Consejeria de Educacion, Junta de Castilla y Leon (SA256P18), including funding by ERDF/FEDER, the Conselleria d'Educacio, lnvestigacio, Cultura i Esport, and Generalitat Valenciana through the grant AIC0/2019/018. J.A.D.N. acknowledges the Japan Society for the Promotion of Science (JSPS) for supporting the author as International Research Fellow.