Second-order nonlinear optical properties of saccharide materials

摘要

ide materials are potential candidates for frequency conversion applications. In addition to being chiral, which ensures crystallization in a space-group relevant for three-wave mixing processes, they generally possess useful physical and optical properties. We have examined the powder second harmonic generation efficiencies of both saturated saccharides and sugars with simple polar $pi@-functionalities. Powder efficiencies of up to 5 times that of sucrose were observed for simple saturated sugars, whereas values of 18 times sucrose (or 0.45 $MUL urea) were observed for unsaturated saccharide derivatives. We have noted that for both classes of material, there is a tendency for more efficient nonlinear compounds to reside in a monoclinic rather than an orthorhombic space-group. We have also noted that there appears to be a correlation between the phase-matching potential and the crystal symmetry.