The nonlinear optical properties of the monoclinic D-isoascorbic acid crystal

D-Isoascorbic acid (C6H8O6) crystals belonging to the monoclinic space group P2(1) are grown from aqueous solution employing slow cooling technique. The grown crystals possess blocky morphology with (100) (010) and (001) prominent faces. Thermal analysis shows that the crystals are stable up to 162 degrees C and decompose immediately after melting. The optical transmission lower cutoff is determined to be 300 nm. The Kleinman conjecture, applicable to second-order nonlinear coefficients, was violated as the optical transmission was dependent on the state of the incident light polarization. The principal dielectric frame of the crystal was determined using conoscopy and is found to be rotated about the crystallographic b-axis. Non-collinear SHG rings up to second order were observed which helped to locate phase matching directions. The second harmonic conversion efficiency of the crystal is measured to be 3x that of a KDP crystal by both single crystal phase matching and Kurtz powder techniques. Surface laser damage thresholds at 1064 and 532 nm are determined to be 9.7 and 4.2 GW/cm(2), respectively.