OPTICAL SPECTROSCOPY OF YB3-XF2( IONS IN CAXCD1)

Optical properties of Yb3+ ions in CaxCd1-xF2 (x = 0.30) crystals are investigated. Photoluminescence and absorption spectra of the intra-io n transitions were measured in a wide temperature range (4 - 300 K). I t was found that position and shape of the Yb3+ zero-phonon emission l ines exhibit a noticeable temperature dependence, particularly at temp eratures T < 50 K. In the same temperature limits, the position and th e shape of the Yb3+ zero-phonon absorption lines do not change signifi cantly. It was found that the measured shift between energy of the emi ssion and absorption zero-phonon lines is due to the efficient energy migration among the Yb3+ ions.