Project C04 - Silicon-Integrated Transmitter and Receiver Components for Multi-Color Imaging and Broadband CW Spectroscopy

Principal Investigator: Prof. Dr. Ullrich Pfeiffer, BUW IHCT

This project aims to explore compact, ultra-broadband transceiver front-ends in silicon technology for multi-color imaging and broadband CW spectroscopy. Today’s spectroscopy systems in the terahertz frequency range are usually based upon optoelectronic components. Although these systems naturally offer high bandwidth, they are bulky and thus lack the portability to be used in future mobile spectroscopes. In contrast, silicon-based semiconductor technology offers low-cost potential and unmatched compactness, but it is severely limited in operational frequency and bandwidth. This project will challenge these limitations by means of a novel conceptual approach to silicon-based terahertz front-end design.

Along these lines, a coherent multi-color imaging concept is proposed. It utilizes tunable broadband transmitter and receiver circuits that operate at several harmonics at the same time. In analogy to the terminology for visible light, these harmonics can be mapped to different colors. Each of these colors contains spectroscopic information about the interfering materials. Within this project, we aim to push the operational bandwidth of the multi-color system to 0.15-1.5 THz in order to ultimately enable gap-less extraction of the spectroscopic information in a decade of bandwidth. Additionally, the front-ends are anticipated to provide adjustable polarization sensitivity for measurements of depolarization effects.

The central long-term research question within this project is whether the necessary breakthroughs can be achieved to enable full coverage of the 0.15-1.5 THz band with a high imaging signal-to-noise-ratio (SNR) concurrently. In order to answer that question, several advanced circuit techniques will be investigated based on state-of-the-art SiGe-HBT technology. C04 provides full-coverage over a decade of bandwidth from 0.15-1.5 THz (up to 4 THz in phase 3) for the measurement of the dispersive reflection of the electromagnetic radiation in a compact silicon transceiver. This will enable high spectral resolution and polarization diversity for ellipsometric measurements.

In summary, C04 provides the required portable spectroscopy hardware to the MARIE consortium and is thus a fundamental contribution to the vision of MARIE.