Single-crystal film of a combination of organic materials involving a molecular salt and a laser dye; Electro-optic effect

Organic single-crystal films involving a combination of a molecular salt (DAST) and a laser dye (IR-125) have been grown on quartz substrates using the modified shear method. Polarized optical microscopy, polarization-dependent optical absorption, x-ray diffraction and electro-optic effect have been measured to characterize the film. The dipole axis of DAST is oriented close to parallel to the substrate. The IR-125 molecule appears to be oriented close to perpendicular to the dipole axis of DAST. The optical gap of the film is about 1.4 eV. The electro-optic coefficient ( r 11 ) as measured by the field-induced birefringence is ∼300 pm/V at 633 nm. Such films are promising for various photonic applications.