AUTHOR=Müller Jan , Ramsteiner Ingo B. , Fieß Reinhold , Neumann Cornelius 

TITLE=High-radiance phosphor-converted light sources for fluorescence analysis

JOURNAL=Advanced Optical Technologies

VOLUME=Volume 13 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/advanced-optical-technologies/articles/10.3389/aot.2024.1510954

DOI=10.3389/aot.2024.1510954

ISSN=2192-8584

ABSTRACT=Laser-excited remote phosphor (LERP) light sources have gained significant importance in
lighting and display applications due to their unique brightness and color rendering qualities.
Beside their known advantages for these applications, we found that they also offer a much
less explored potential for sensor applications such as quantitative fluorescence analysis. This
applies especially when sophisticated optics under space and cost constraints call for low etendue
sources with highly stable spectral properties. In this paper, an example for such an application is
given. The purpose of our research is to assess currently available phosphor materials and design
a light source for our particular reference application. For this purpose, a characterization setup
was set up that compares different phosphors excited by small laser spots with diameters between
100 µm and 280 µm in terms of emitted spectral radiance, incident laser power and irradiance.
The investigations identify two suitable phosphors, including a phosphor that closes the gap in
the blue and green wavelength range. Furthermore, the importance of small laser spots was
demonstrated, which allows to reduce the laser power to simplify light source design and to save
costs. The presented research proposes a functional set of phosphors for the above-mentioned
application and at the same time presents the current limits of LERP light sources. We remain
convinced in the described application field for LERP sources and hope that the needs elaborated
in this work will stimulate research and development of novel phosphor materials.