This paper reports the main spectroscopic characterizations and laser
experiments carried out on two new crystal hosts: the yttrium orthosil
icate Y2SiO5 and the silicate oxyapatite SrY4(SiO4)(3)O (hereafter not
ed SYS), doped with ytterbium and erbium fora 1.55 mu m laser emission
and with thulium for a 2 mu m emission. Four new lasers have been dem
onstrated at 1.554 mu m, 1.576 mu m, 1.99 mu m and 2.05 mu m for respe
ctively Yb,Er:SYS;Yb,Er:Y2SiO5;Tm:SYS and Tm:Y2SiO5. If for Yb,Er-codo
ped materials laser performances are still poor compared with the Yb,E
r phosphate glass, the Tm-doped materials exhibit laser performances s
imilar to the Tm:YAG and look very promising.