NONLINEAR-OPTICAL PROPERTIES OF MODIFIED DR1 SILICA FILMS WITH HIGHLYORDERED STRUCTURES/

Crosslinkable organic NLO chromophore (DRS) has been prepared and chem ically incorporated into silica matrices using a sol-gel process. By m onitoring the decay of UV absorbance as a function of time and tempera tures, a number of electrically poled DRS/silica matrice system has be en investigated to elucidate the relaxation behaviors of the oriented organic chromophore by the poling. The value of the second order NLO c oefficient d(33) was 47 pm/V for the DRS/silica matrice films with 0.4 mu m thickness. In addition, from the result of dramatic decreasing o f UV absorbance after poling, it is speculated that the DRS may act as a liquid crystalline mesogenic groups and effectively oriented by the poling at the phase (nematic) transition temperature (80 degrees C) a nd locked in by the crosslinking. The crosslinking reactions between s ilica matrices and DRS chromophores have been proved using Si-29 solid NMR measurement.