In this paper

the spectral properties of Ho

3+

ions in ZnS have been investigated systematically. By means of emission spectra excited by different wavelength [Fig.2-3]

excitation spectra [Fig.4]

fluorescent decay and temperature dependence of emission intensities

we have got the following results. 1)Transitions between 29000cm

-1

-14000cm

-1

have been identified. Emis-sion-from the excited states

5

G

5

5

G

4

5

G

5

5

G

6

3

K

8

5

F

2

5F3

5S2 and excitation to the states

5

G

6

5

G

5

3

K

7

3

H

6

5

G

3

(

3

L

9

) have been observed [Fig. 5].