Our research lab focuses on applied and fundamental research in the fields of novel optical sensing materials and signal processing for advanced sensing. We specialize in broad-band optical spectroscopy of application materials. Our goal is to develop robust and accurate solutions in sensing technology for society.
A first focus of the group is on the application of THz technology. Terahertz radiation is situated in the electromagnetic spectrum between microwaves and infrared and is characterised by a frequency range from 100 GHz to 10 THz, i.e. wavelengths between 3 mm and 30 渭m. A peculiarity of THz radiation is that it penetrates many objects that are opaque to infrared and visible light. Despite, the technology has not yet found a breakthrough (industrial) application. The focus of our activities in the field of applications of THz spectroscopy is precisely aiming at answering this question: what are bottlenecks for THz applications to become widely adopted and have societal impact? Signal processing of raw THz signals in order to obtain reliable material parameters is a major hurdle. Our research hereto focusses on the development of model-based, data-based and hybrid physics-based approaches. Furthermore, we choose application domains with present societal interest, such as the inspection of coffee beans for sorting, leaf wetness for pest control and the inspection of goods in the field of security. Combining both aspects, we develop sensor technologies and build sensor demonstrators to evince the potential impact of THz technology for applications.
A second research focus of the group is on selective hydrogen sensing using novel sensing materials at infrared frequencies. In a future hydrogen-based economy, where hydrogen is ubiquitous, ensuring safety is paramount. However, all commercial hydrogen sensors are cross-sensitive to other gasses. In our research, we aim to create new sensing concepts using on the one hand reminiscent features of functionalized sensing materials in order to create specificity, and on the other hand we aim to enhance the sensing sensitivity of optical sensors by integrating functional materials with photonic metastructures. Hereto, we study quantum materials for their intriguing novel material properties and concomitant potential use as sensing material for advanced sensing. Metal hydrides, for instance, are metals that absorb hydrogen and undergo a metal-to-insulator transition. This phase transition is evinced as a drastic optical change across an entire optical broad-band spectrum. In this research we aim at understanding the nature of this transition and use it as a novel, accurate and selective way of hydrogen sensing. Of equal interest are the class of perovskite materials, such as LaAlO3 and SrTiO3, where we study fundamental properties of light-matter interactions, such as phonon-polaritons, and their application as novel quantum sensing materials.