Laser beam profilometry is an important scientific task with well-established solutions for beams propagating in air. It has, however, remained an open challenge to measure beam profiles of high-power lasers in ultra-high vacuum and in tightly confined spaces. Here we present a novel scheme that uses a single multi-mode fiber to scatter light and guide it to a detector. The method competes well with commercial systems in position resolution, can reach through apertures smaller than 500×500 µm² and is compatible with ultra-high vacuum conditions. The scheme is simple, compact, reliable and can withstand laser intensities beyond 2 MW/cm². (read more here)

Optics Express:

C. Brand, K. Simonović, F. Kiałka, S. Troyer, P. Geyer, M. Arndt
A fiber-based beam profiler for high-power laser beams in confined spaces and ultra-high vacuum,
Optics Express 28/5, 6164-6171 (2020). DOI 10.1364/OE.387650