Measurement and calculation of second - harmonic generation in single - crystal spheres : application to d coefficients of D - mannitol , C 6 H 14 O 6

The measurement of d coefficients from second-harmonic efficiencies in crystal spheres is studied. KH2PO4 is used as a reference for measurements in spheres and with the Maker-fringes technique. As an example, unknown d coefficients in an orthorhombic mannitol, C6H14O6, in which large coefficients of optical rotation have recently been measured, are determined as d123 = 0.06(2) pm V −1 and compared with a calculation performed with a dipole–dipole interaction model in which the effect of the electric field of a light wave on the crystal structure is applied. Modelling of the basic parameters in the calculation gives good agreement with the experimentally derived values. The accuracy in determining the d coefficients, achievable with spheres is limited to 20%.