This research opportunity focuses on the development of wideband THz mixers operating at elevated temperatures (up to 60 K), which can be achieved in space without using liquid helium. Such mixers will be important for the advancement of astrophysical and planetary heterodyne receivers and for their deployment on platforms with limited resources (e.g., SmallSat). At this time, we pursue hot-electron bolometer (HEB) mixers based on MgB2 superconductor [1] and quantum-well based mixers based on intersubband transitions in AlGaAs/GaAs [2]. The main application of these detectors would be in the THz line spectroscopy of the interstellar molecular clouds and various gaseous bodies (atmospheres, volcano plumes, geysers, comet comae, etc.) in the solar system. Integration of the mixers with Quantum Cascade Laser (QCL) local oscillators (LO) is of particular interest. Also important are technologies allowing for integration of these mixers into arrays. The activities include laboratory investigations and optimization of the mixer devices (IF bandwidth, noise temperature, LO power, THz coupling, etc.) and also development and construction of prototype receivers (single-pixel and multi-pixel) based on mechanical cryocoolers. Previous experience with THz mixers, detectors, receivers, measurements, and corresponding laboratory techniques is required. Microfabrication experience is desirable.

1. D. Cunnane et al., IEEE Trans. Appl. Supercond. 27, 2300405 .
2. C. Yoo et al., Appl. Phys. Lett. 116, 013504 .

Applications with citizens from Designated Countries will not be accepted at this time, unless they are Legal Permanent Residents of the United States. A complete list of Designated Countries can be found at: https://www.nasa.gov/oiir/export-control.

Eligibility is currently open to:

• U.S. Citizens;
• U.S. Lawful Permanent Residents (LPR);
• Foreign Nationals eligible for an Exchange Visitor J-1 visa status; and,
• Applicants for LPR, asylees, or refugees in the U.S. at the time of application with 1) a valid EAD card and 2) I-485 or I-589 forms in pending status

• Degree: Doctoral Degree.