Er-doped glasses have attracted much research interests due to their application in the area of optical communications

such as fiber amplifiers and lasers

and infrared solid-state lasers.To account for the optical absorption and in turn radiative properties of excited states

the Judd-Ofelt theory has been successfully applied to most of the lanthanide ions.In this paper

the experimental and theoretical oscillator strengths of some levels of Er

3+

ion in Cd

3

Al

2

Si

3

O

12

glass(CAS glass in brief) were calculated using the absorption spectra and Judd-Ofelt theory.The root-mean-square deviation is only 3.30×10

-7

.This result indicates that the theory is in well accord with the experiment results.Based on a least-square fit between experimental and theoretical oscillator strengths

the intensity parameters were determined.The results are Ω

2

=6.42×10

-20

cm

2

;Ω

4

=1.53×10

-20

cm

2

;Ω

6

=0.69×10

-20

cm

2

.Then the radiative transition proba-bility A

radiative lifetime r

branching ratio βand integrated emission cross-sections of radiative transitions of Er

3+

in this glass at room temperature were calculated.According to the large integrated emission cross-emission(1.402×10

-18

cm) and the long lifetime(8.062ms) of the transition of

4

I

13/2

→

4

I

15/2

of Er

3+

in CAS glass

it can be concluded 1.534μm laser oscillation of Er-doped CAS glass is possible to be demon-strated.In addition

this glass has several advantages

such as easy-made

scale-varied

easy-fibered and ad-justable host composition along with their high chemical durability and thermal stability.Therefore

Er-doped CAS glass is a potential near infrared solid-state laser material.