POWDER 2ND-HARMONIC GENERATION EFFICIENCIES OF SACCHARIDE MATERIALS

Saccharide materials are potential candidates for frequency conversion applications. In addition to being chiral, which ensures crystallizat ion in a space group necessary for three-wave mixing processes, they g enerally possess useful physical and optical properties. We have exami ned the powder second harmonic generation efficiencies of both saturat ed saccharides and sugars with simple polar pi-functionalities. Powder efficiencies of up to 5 times that of sucrose were observed for simpl e saturated sugars, whereas values of 18 times sucrose (or 0.45 X urea ) were observed for unsaturated saccharide derivatives. We have noted that for both classes of material, there is a tendency for more effici ent nonlinear compounds to reside in a monoclinic rather than an ortho rhombic space group. We have also noted that there appears to be a cor relation between the phase-matching potential and the crystal symmetry . In addition, two promising saccharide materials have been identified for frequency conversion applications, based on their powder second-h armonic generation efficiencies, their phase-matching capabilities, an d their UV transparency.