ErAs:In(Al)GaAs-based Photoconductive Terahertz Device Arrays

The Terahertz devices and systems laboratory offers a position (full time, E13, 100%) yet limited to a duration of 36 months with a targeted starting date of November 1st 2022 in the framework of the SFB/TRR 196 “MARIE”, project C07 and partially M01 (https://trrmarie.de/sfbtrr196marie/ ). The research topic are arrays of photoconductive materials based on ErAs:In(Al)GaAs for generation and detection of THz radiation (100 GHz-10 THz). These so-called photoconductors are driven by a (telecom-) laser signal (either a short pulse with a pulse duration <100 fs [1,2], or two continuous-wave lasers with a difference frequency of the desired THz frequency [2,3]). Absorption of the laser signal leads to a modulation of the conductivity of the material at THz frequencies. If the device is operated as THz source, a further DC bias is applied, leading to a THz-modulated current that is subsequently radiated by an attached antenna. If operated as detector, a THz signal is directed onto an antenna which converts the THz radiation to a THz bias. This is used to bias the photoconductive material that is, at the same time, illuminated with a laser signal as described previously. This way, the received THz bias is mixed with the laser signal, yielding a DC component that is proportional to the THz field strength [4]. The focus will lie on integrated detector array structures. However, some applications will also require development of photoconductive sources, in particular for pulsed operation [5]. The work will include, amongst others, the design of the devices and their antenna structures, processing of the devices in a clean room, design of photonic integrated circuits, integration of finished devices with electronics and optical components, characterization of the developed structures, carrying out applications, as well as paper writing and conference contributions. Research is performed within an international team with friendly atmosphere.