eprintid: 1558275 rev_number: 26 eprint_status: archive userid: 608 dir: disk0/01/55/82/75 datestamp: 2017-06-01 14:59:34 lastmod: 2021-10-07 21:56:07 status_changed: 2017-09-14 11:27:51 type: article metadata_visibility: show creators_name: Thompson, RJ creators_name: Siday, T creators_name: Glass, S creators_name: Luk, TS creators_name: Reno, JL creators_name: Brener, I creators_name: Mitrofanov, O title: Optically thin hybrid cavity for terahertz photo-conductive detectors ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F46 keywords: Science & Technology, Physical Sciences, Physics, Applied, Physics, GAAS, OPTOELECTRONICS, GENERATION, ANTENNAS, DEVICES note: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. abstract: The efficiency of photoconductive (PC) devices, including terahertz detectors, is constrained by the bulk optical constants of PC materials. Here, we show that optical absorption in a PC layer can be modified substantially within a hybrid cavity containing nanoantennas and a Distributed Bragg Reflector. We find that a hybrid cavity, consisting of a GaAs PC layer of just 50 nm, can be used to absorb >75% of incident photons by trapping the light within the cavity. We provide an intuitive model, which describes the dependence of the optimum operation wavelength on the cavity thickness. We also find that the nanoantenna size is a critical parameter, small variations of which lead to both wavelength shifting and reduced absorption in the cavity, suggesting that impedance matching is key for achieving efficient absorption in the optically thin hybrid cavities. date: 2017-01-23 date_type: published publisher: AMER INST PHYSICS official_url: http://dx.doi.org/10.1063/1.4974482 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1210216 doi: 10.1063/1.4974482 lyricists_name: Mitrofanov, Oleg lyricists_name: Thompson, Robert lyricists_id: OMITR95 lyricists_id: RJTHO70 actors_name: Dewerpe, Marie actors_id: MDDEW97 actors_role: owner full_text_status: public publication: Applied Physics Letters volume: 110 number: 4 pages: 5 issn: 1077-3118 citation: Thompson, RJ; Siday, T; Glass, S; Luk, TS; Reno, JL; Brener, I; Mitrofanov, O; (2017) Optically thin hybrid cavity for terahertz photo-conductive detectors. Applied Physics Letters , 110 (4) 10.1063/1.4974482 <https://doi.org/10.1063/1.4974482>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1558275/1/Mitrofanov_1%25252E4974482.pdf