Thermo-optic characterization of Yb:CaGdAlO 4 laser crystal

Pavel Loiko (1) , Frederic Druon (2) , Patrick Georges (2) , Bruno Viana (3) , Konstantin Yumashev (1)

1 Center for Optical Technologies and Department of Materials Science and Engineering
2 Laboratoire Charles Fabry / Lasers
3 IRCP - Institut de Recherche de Chimie Paris

Principal thermo-optic coefficients (TOCs), dn o /dT and dn e /dT, are measured for Yb:CaGdAlO 4 crystal, for the first time, to our knowledge. At the wavelength of ~1 μm, they equal –7.6 and –8.6 (× 10 −6 K −1), accordingly. Thermal coefficients of the optical path (TCOP) are determined for this crystal for the principal crystal cuts (a-cut and c-cut) and light polarizations (π or σ). Thermo-optic dispersion formulas are evaluated for both TOC and TCOP coefficients. Optical power of thermal lens is measured for diode-pumped a-cut Yb:CaGdAlO 4 ; it is also calculated on the basis of measured material parameters. Thermal conductivity of CaGdAlO 4 crystal is measured versus Yb concentration. The results indicate that a-cut Yb:CaGdAlO 4 can provide really " athermal " behavior.

Mots clés: diode-pumped; OCIS codes: (1403380) Laser materials; (1406810) Thermal effects; (1403480) Lasers

Domaines: Optique [physics.optics]

Pavel Loiko, Frederic Druon, Patrick Georges, Bruno Viana, Konstantin Yumashev. Thermo-optic characterization of Yb:CaGdAlO 4 laser crystal. Optical Materials Express, 2014, 4 (11), pp.2241-2249. ⟨10.1364/OME.4.002241⟩. ⟨hal-01163224⟩