Thermal behaviour of ytterbium-doped fluorite crystals under high power pumping

Justine Boudeile (1) , Julien Didierjean (1) , Patrice Camy (2) , Jean-Louis Doualan (2) , Abdel [e-mail] Benayad (2) , Vivien Ménard (2) , Richard Moncorgé (2) , Frédéric Druon (1) , François Balembois (1) , Patrick Georges (1)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Elsa
2 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique

We report an in situ thermal study of Yb-doped fluorite crystals Yb:CaF2 and Yb:SrF2 under high power pumping, with or without laser operation. The experiment combines simultaneously thermography and measurement of the thermal aberrations. This setup allows us to measure temperature gradients, thermal lens, and absorption coefficients. From these measurements, we evaluate the thermal conductivity, fractional thermal load, and thermo-optic coefficient. Great differences are observed between the lasing and non lasing regimes. Our measured thermal lenses are greater than what are expected from the thermo-optic parameters found in previous work. Based on this thermal study, we design a laser cavity operating with large output power and TEM00, leading to better performances for Yb:CaF2 than Yb:SrF2.

Keywords: ytterbium; OCIS codes: (120.6810) Thermal effects; (140.3480) Lasers; diode-pumped; (140.3615) Lasers; ytterbium.

Domains: Optics [physics.optics]

Justine Boudeile, Julien Didierjean, Patrice Camy, Jean-Louis Doualan, Abdel [e-mail] Benayad, et al.. Thermal behaviour of ytterbium-doped fluorite crystals under high power pumping. Optics Express, 2008, 16, pp.10098-10109. ⟨cea-00344113⟩