![Self-Focusing in Pulsed and Continuous Regime in Photorefractive Crystals: KNbO
<sub/>3</sub>
, LiNbO
<sub/>3</sub>
, Sr
<sub/><i>x</i>
</sub>
Ba
<sub/>
1 −
<i>x</i>
</sub>
Nb
<sub/>2</sub>
O
<sub/>6</sub>]()
Self-Focusing in Pulsed and Continuous Regime in Photorefractive Crystals: KNbO
<sub/>3</sub>
, LiNbO
<sub/>3</sub>
, Sr
<sub/><i>x</i>
</sub>
Ba
<sub/>
1 −
<i>x</i>
</sub>
Nb
<sub/>2</sub>
O
<sub/>6</sub>Hesse, C.; Wolfersberger, D.; Fressengeas, N.; Kugel, G. · Ferroelectrics · 2003