Developments in Ceramic Materials Research

Fluorescence
Fluorescence, a.u.
Optical Fluoride and Oxysulfide Ceramics: Preparation and Characterization 71
250 CaF2:Er
200
150
3+ (5%)
ceramic
4
I13/2 --> 4 I15/2 exc = 974 nm
T=300 K
a)
100
50
0
1
1400 1450 1500 1550 1600 1650
powdered
ceramic
τ=6.7 ms
4 I13/2
λ, nm
ceramics
τ=15.7 ms
time, sec
CaF 2:Er 3+ (5%)
T=300 K
λ exc =974 nm, λ det = 1.53 μm
0.00 0.02 0.04 0.06
Figure 17. Fluorescence spectrum measured under CW laser excitation with 810 nm wavelength at the
4 I13/2 → 4 I 15/2 transition in the CaF 2:Er 3+ (5%) ceramic sample (B(2)-39-05) at room temperature – a, and
fluorescence kinetics decay of the 4 I 13/2 level measured under pulsed laser excitation with 1.53 µm
wavelength detection at room temperature – b in the CaF 2:Er 3+ (5%) (B(2)-39-05 sample) ceramics – 1
and powdered ceramic sample – 2.
OXYSULFIDE OPTICAL CERAMICS
Powder phosphors based on La, Gd, and Y oxysulfides hold unique position among other
phosphors due to highly- efficient conversion of different types of radiation including UV,
cathode beam and X – rays. These materials have a high density (La2O2S – 5.77 g/cm 3 ,
Gd2O2S - 7.33 g/cm 3 , Y2O2S - 4.089 g/cm 3 ) that provides high x-ray adsorption coefficients
b)