Crystal growth and spectroscopic investigation of Yb2+-doped fluoride crystals

In this presentation we report on the preparation and spectroscopic propert ies of Yb2+-doped MgF2, KMgF3, LiCaAlF6, and LiSrAlF6 with respect to the r ealization of a tunable solid state laser based an a inter-configurational transition of Yb2+. All materials exhibit broadband emission in the short-w avelength region due to a 5d-4f transition. The peak emission wavelengths a nd bandwidths at room temperature are in particular 485 nm and 4510 cm(-1) for Yb2+: MgF2, 400 nm and 3890 cm(-1) for Yb2+ : KMgF3, 393 nm and 3260 cm (-1) for Yb2+ : LiCaAlF6, 440 nm and 5180 cm(-1) for Yb2+ : LiCaAlF6, respe ctively. The emission can he excited in the energy level of the 4f(13)5d co nfiguration. An energy level scheme for Yb2+ : MgF2 in the strong field ass ignment is proposed. The room temperature decay time of the Yb2+ emission i s 52 mus in MgF2, 80 mus in KMgF3, 5.4 mus in LiCaAlF6 and 9.9 mus ill LiSr AlF6, respectively.