“…In one of their important applications, for instance, diode-pumped Nd 3+ -doped lasers have become widely recognized as all-solid-state visible laser sources for nonlinear frequency conversion into blue, green, orange and red [1][2][3][4][5][6]. Compared with conventional Nd 3+ single-crystal laser materials, such as Nd:YAG [7][8][9], Nd:GGG [10,11], Nd:YVO 4 [12,13], Nd:GdVO 4 [14], Nd:YLF [15,16] and Nd:YAP [17,18], in recent years, laser host materials possessing a broad bandwidth have attracted more and more research interest, because these broad bandwidth laser mat erials provide the opportunity to pursue tunable lasers and ultrashort pulse lasers using mode-locking technology. Such a broad bandwidth resulting from inhomogeneous broadening behavior is attributed to multiple substitutional sites with low symmetry, which enhances the structural disorder to a certain extent [19,20].…”