News | 01-02-2022

Journal publication by IKZ authors selected as 'Editors’ Pick'

IKZ researcher Stefan Püschel’s recent work on 'Solid-state laser cooling in Yb:CaF₂ and Yb:SrF₂ by anti-Stokes fluorescence' was selected as an 'Editors’ Pick' in the latest issue of the prestigious Journal 'Optics Letters' by Optica (former OSA). This is a valuable appreciation of his work, as less than 5% of all papers published in Optica Journals are selected as Editors’ Picks by the Journal's Associate Editors to highlight papers of excellent scientific quality that will be exciting to the Journal's readers.

Photography of the irradiated ytterbium-doped calcium fluoride sample. The sample is placed on thin glass fibers to thermally decouple it from the copper holder.

Stefan Püschel is a doctoral student in the junior research group 'Fluoride Crystals for Photonic Applications' of Dr. Hiroki Tanaka and pursues his PhD in close collaboration with the research team at the Center for Laser Materials (ZLM) headed by Dr. Christian Kränkel. His research target is to develop new and improve the quality of existing crystalline materials for solid-state laser cooling. In this astonishing process, crystals of very high quality can be cooled by simple irradiation with laser light, if the laser wavelength is longer than the average wavelength of the fluorescence. In Stefan Püschel’s paper, this effect is shown for the first time to appear in the common fluoride crystals CaF2 and SrF2 doped with Yb3+, revealing that cooling down to 150 K is potentially feasible.



Stefan Püschel, Felix Mauerhoff, Christian Kränkel, and Hiroki Tanaka
Solid-state laser cooling of Yb:CaF2 and Yb:SrF2 by anti-Stokes fluorescence
Optics Letters 47 (2), 333-336 (2022)