The correlation of post disposing effect on optical properties of Mg:Fe:Mn:FiNbO_3 crystals

摘要

The congruent tri-doped Mg:Fe:Mn:FiNbO_3 crystals have been grown by Czochralski method in air atmosphere. The crystal samples are reduced in Li_2CO_3 powder at 500 °C for 24 hours or oxidized for 10 hours at 1100 °C in Nb_2O_5 powder. Compared with as-grown Mg:Fe:Mn:FiNbO_3, the absorption edge in UV-Vis. absorption spectrum of the oxidized sample or the reduced shifts to the red. The post-disposal, oxidation or reduction disposing has no effect on O-H vibration absorption peak in infrared region. In two coupling experiments we determine the writing time, maximum diffraction efficiency and the erasure time of crystal samples in the same conditions. The results indicate that oxidation and reduction disposing has great effect on the holographic recording properties of these crystals. The reduced crystal exhibits the fastest response time 145s and the biggest diffraction efficiency 67% among the crystal series. The mechanism of post-disposing effect on the holographic recording properties of these crystals. The mechanism of post-disposing effect on the holographic recording properties of Mg:Fe:Mn:FiNbO_3 crystals has been investigated.