ROOM-TEMPERATURE CW LASER OPERATION AT SIMILAR-TO-1.55-MU-M (EYE-SAFERANGE) OF YB-ER AND YB-ER-CE-CA2AL2SIO7 CRYSTALS

Room-temperature CW laser operation at 1.55 mu m of Yb:Er:Ca2Al2SiO7 ( CAS) single crystal pumped at 940 nm and 975 nm has been achieved for the first time. Introduction of a third doping ion, Ce3+, decreases th e Er3+4I11/2 excited-state lifetime and improves the laser properties. For Yb:Er:Ce:CAS single crystal, a maximum of 20 mW output power is p roduced for 285 mW absorbed power, With this material, a low threshold of 20 mW and a relatively high slope efficiency of similar to 5.5% ar e obtained. Preliminary results indicate possible improvement in the n ear future. Experimental threshold values and laser properties of CAS crystals with various compositions are in good agreement with calculat ions, performed using the rate-equations modeling. Comparison with a Y b:Er:phosphate glass laser is also presented.