In recent years

Er

3+

-doped glasses with a broad 1.5 μm emission band originating from

4

I

13/2

-

4

I

15/2

transition of Er

3+

have been extensively investigated for use in erbium-doped fiber amplifiers (EDFA). Among the reported materials

Er

3+

-doped telluride glasses exhibited a wide 1.5 μm emission band and a large stimulated emission section and high 1.5 μm emission efficiency. However

as a host for EDFA

telluride glass has some major drawbacks. One of them is the phonon energy of the glass is about 770 cm

-1

which leads to the

4

I

11/2

-

4

I

13/2

nonradiative relaxation rate too slow to allow efficient pumping at 980 nm. To overcome this drawback

S. Shen

et al

. added WO3

with vibronic energy of W-O bond of 920 cm

-1

into the glass to form tungsten-tellurite glasses. This composition modification increased the nonradiative relaxation rate of the

4

I

11/2

-

4

I

13/2

transition and made improvement of population feeding efficiency of

4

I

13/2

from the

4

I

11/2

level pumped at 980 nm. In this paper

P

2

O

5

was introduced into Er

3+

-doped tungsten-tellurite glasses. Emission

absorption and upconversion spectra of the glasses are studied. It is observed that the nonradiative relaxation rate of

4

I

11/2

-

4

I

13/2

transitions and the 1.5 μm emission efficiency increases with the increase of P

2

O

5

content

while

the upconversion luminescence was suppressed. The nonradiative relaxation rate of

4

I

11/2

-

4

I

13/2

transition in a glass with 6% P

2

O

5

is about 3.5 times greater than that without P

2

O

5

. The present results indicate that telluride glasses with P

2

O

5

addition may be a promising candidate medium for broadband erbium-doped fiber amplifiers with good performance under the pumping of 980 nm.