ZENG Xian-lin, WANG Jin-hao, XIA Hai-ping, ZHANG Jian-li, SONG Hong-wei, ZHANG Jia-hua, YAO Lian-zeng. Absorption Spectra of LiNbO<sub>3</sub>, Fe:LiNbO<sub>3</sub>, and Zn:Fe:LiNbO<sub>3</sub> Crystals Grown by Bridgman Method[J]. Chinese Journal of Luminescence, 2004,25(4): 435-440
ZENG Xian-lin, WANG Jin-hao, XIA Hai-ping, ZHANG Jian-li, SONG Hong-wei, ZHANG Jia-hua, YAO Lian-zeng. Absorption Spectra of LiNbO<sub>3</sub>, Fe:LiNbO<sub>3</sub>, and Zn:Fe:LiNbO<sub>3</sub> Crystals Grown by Bridgman Method[J]. Chinese Journal of Luminescence, 2004,25(4): 435-440DOI:
crystals grown by Bridgman method were measured and investigated.The characteristics of the absorption were explained
and the effects of growth processing on the absorption spectra were also discussed.The results indicate that the absorption edge of lithium niobate shifts to longer wavelength
and the absorption intensity in the range of 350
4
50nm band increases along the direction of crystal growth.The reason of above causes is lacking of lithium composition in crystal
which resulted from the volatilization and segregation of lithium in growth period.A band at 480nm which attributed to Fe
2+
ion absorption was observed in Fe:LiNbO
3
crystal
and it was found that the intensity of the band increases along the growth direction
which means the increase of Fe
2+
ion along the direction
and the incorporation of Fe in LiNbO
3
resulted in a red shift of absorption edge.However
the concentration of Fe
2+
ion in the obtained crystal increases obviously compared with that of Fe:LiNbO
3
in same quantity of Fe dopant
which was quite different from that of crystal grown by the Czochralski method.When ZnO in
w
(ZnO)=1.7% was doped
a blue shift of absorption edge was observed
but a slightly red shift for
w
(ZnO)=3.4% ZnO.Among Fe-doped and Zn/Fe co-doped LiNbO
3
crystals
1.7% ZnO doped Fe:LiNbO
3
has biggest change of Fe
2+
ion mass fraction from bottom to top part of crystal.A stronger suppressing effect on Fe
2+
concentration in Zn:Fe:LiNbO
3
single crystals resulted from doping
w
(ZnO)=1.7% than
w
(ZnO)=3.4%.The effect of the special growth technology on the Fe