SrMoO

4

:Yb

Er nano-sized up-conversion luminescent powder was prepared by sol-gel method in the presence of citric acid.The impact of different proportion of /Yb

3+

to Er

3+

on the up-conversion luminescent intensity was discussed.The experiment showed that when the proportion of /Yb

3+

to Er

3+

is 7:1

the up-conversion luminescent intensity is the strongest.The sample was characterized via XRD

TME and emission spectrum.The results showed that SrMoO

4

:Yb

Er belongs to pyramidal system;the grain size of SrMoO

4

:Yb

Er is under 100 nm

and belongs to polycrystals.Under 980 nm laser diode(LD) excitation

two strong green emissions and a wake red emission

which centered around 526

558

652 nm

respectively

are observed at room temperature.They correspond to

2

H

11/2

4

I

15/2

4

S

3/2

4

I

15/2

and

4

F

9/2

4

I

15/2

transitions of Er

3+

ion

respectively.According to the relationship between pump power and luminescent intensity

it was concluded that the both the green and the red emission all are dominated by two-photon process.