Spectroscopic properties of Er^(3+) doped AlF_(3) La_(2)O_(3) Al_(2)O_(3) SiO_(2

Er^(3+)-doped fluoride lanthanum aluminosilicate glasses with compositions of (65-x/2)SiO_(2).(25-x/2)Al_(2)O_(3).xAlF_(3).9.1La_(2)O_(3).0.6Er_(2)O_(3).0.3Yb_(2)O_(3) (x = 4, 8, 12, 20, 30) (mol%) were prepared and their glass transitiontemperatures and spectroscopic properties were investigated. T