Structural and spectroscopic characterization of nominal Yb3+: Ca-8 La-2 (PO4)(6) O-2 oxyapatite single crystal fibers grown by the micro-pulling-down method

Yb-doped Ca8La2(PO4)(6)O-2 (CLPA) single crystals with the apatite-type str ucture and having <0001> orientation were grown by the micro-pulling-down ( mu -PD) method. The apatite structure is represented by the monophased fiel d of Ca-8(La2-xYbx)-(PO4)(6)O-2 (CLYPA) where it is assumed that 2 Ca2+ sit es are substituted by La3+ and Yb3+ cations. Its monophased range was found to be from x = 0.0 to 0.2. The segregation of Yb3+ in CLPA single crystals and I the maximum Yb3+ concentration are discussed. The crystallinity was studied using X-ray rocking curve analysis. Absorption, emission and fluore scence decay studies of Yb3+ ions in CLPA were also carried out both at low temperature and room temperature. Spectroscopic data reveal Yb3+ ion occup ation within different crystallographic sites of the apatite-type structure . The potential for a diode-pumped Yb3+ laser is evaluated.