Any sensitive detection instrument seeks to isolate a usually very rare signal out of -an often overwhelming amount of- undesired, disturbing background events. Hence, breakthroughs in an instruments’ sensitivity are typically associated with more efficient detection of the former and/or more effective suppression of the latter. For sensitive optical devices this implies that the detection of the desired photons has to be optimised while sources of background or stray light into the photon-detection apparatus need to be minimised. Consequently, the right combination of highly reflective and highly absorbing surfaces is required to efficiently guide the photos of interest to the detection apparatus while maximally absorbing background light before it can enter the sensitive detection region.
Especially, in the region of ultra-violet (UV) light, materials or coatings which exhibit high reflection or absorption characteristics over a wide UV wavelength spectrum remain difficult to identify. Moreover, optical instruments may impose strict requirements on these materials or coatings in addition to their UV reflection or absorption properties. These demands include minimal out-gassing rates and excellent vacuum compatibility, firm structural stability under reoccurring thermal cycling to cryogenic or ‘hot’ temperatures, electrical properties such as high conductivity, formability, or the attainable size of the highly UV reflective or absorbing surfaces.
In a collaborative effort by research institutions with industry partners, this project is determined to develop and characterise novel materials and coatings with the highest reflection or absorption rates over the entire middle to near UV ranges (200-400nm) which additionally also satisfy the requirements listed above.
To benchmark their performance under real instrument conditions as well as to illustrate examples of their wide applicability, these materials and coatings will be first applied in next-generation laser-spectroscopy installations. There, they are envisioned as central ingredients for laser spectroscopy based trace analysis or accurate voltage determination at the parts-per-million level. Once established, these materials and coatings are expected to become important for a wide range of optical and scientific instruments as well as, in the long run, for industrial applications of UV light in general.