The junior research group THz microscopy of the Laboratory for Emerging Nanometrology (LENA) and the Institute of Electrical Measurement Science and Fundamentals of Electrical Engineering (EMG) at TU Braunschweig is headed by Dr. Benedikt Hampel. The research group deals with the fabrication, characterization and application of superconducting sensors, especially for the measurement of high-frequency radiation up to the THz range.
The sensors, also known as Josephson cantilevers, are made of the high-temperature superconductor yttrium barium copper oxide (YBa2Cu3O7). They must be cooled to very low temperatures for measurements. The research group has access to a clean room with extensive equipment for the fabrication and patterning of superconducting layers for the fabrication of the Josephson cantilevers. These are fabricated by pulsed laser deposition (PLD) and subsequently patterned by photo or electron beam lithography in combination with a dry etching process using Ar+ ions.
In the THz microscope, Josephson cantilevers can be moved by a precise positioning system, allowing three-dimensional measurements of high-frequency radiation distributions. Active high-frequency circuits, such as the world's fastest computer chips, can be examined. Alternatively, passive samples can be irradiated and examined with help of a high-frequency generator or far-infrared laser system.