UVALITH advanced optical frequency conversion technology developed for the FET Proactive project QUIC (Quantum Simulation of Insulators and Conductors) toward industrial and biomedical use. Optical frequency converters use nonlinear optical processes such as second harmonic generation to produce coherent light at wavelengths that are not available, or not efficient, with existing laser sources. Importantly, optical frequency converters can reach near-ultraviolet (UVA) wavelengths, employed in biological and medical applications based on fluorescent biomarkers. In QUIC, we have developed a monolithic frequency converter (MFC), in which a single nonlinear optical crystal acts simultaneously as an optical resonator, frequency converter, and tuning system. The resulting device is compact and extremely stable, and efficiently converts inexpensive near-infrared (NIR) light into coherent UVA. UVALITH advanced this patented technology from the laboratory proof-of-principle stage toward a technology level suitable for uptake by industrial and commercial actors, including advances in scalability, versatility and reliability.
Fluorescent markers are extraordinarily valuable to advanced biology and diagnosis because of their specificity: these markers bind to bio-molecules such as DNA or surface proteins, with a specificity that allows them to, for example, distinguish cancer cells from healthy ones. This specificity enables high-resolution identification of intra-cellular components in microscopy and high throughput screening in flow cytometry. In general, fluorescent markers require an excitation wavelength shorter than their emission wavelength, and many important biological markers, including the DNA markers DAPI-DNA, GelRed and Hoechst 33258- DNA, require excitation wavelengths below 375 nm, the shortest wavelength available with a diode laser. For this reason, frequency converters in the UVA range can potentially enable a large expansion in applications of fluorescence-based bio-marker detection.