| 초록 |
We investigated a new acentric organic single crystals based on OHQ (2-(4-hydroxystyryl)-1-methylquinolinium) cations with various counter anions, such as 4-methylbenzenesulfonate, 4-vinylbenzenesulfonate, iodide, and 2,4,6-trimethylbenzenesulfonate for OHQ-T, OHQ-VBS, OHQ-I, and OHQ-TMS. The OHQ crystals exhibit strong tendency for noncentrosymmetric molecular arrangement in crystalline state since strong Coulombic interaction and hydrogen bonds between OHQ cation and sulfonic anions. In particular, OHQ-T crystals show practically perfect order parameter (cos3θp=1.0.) and therefore exhibit large macroscopic optical nonlinearity: βiiieff is 121×10-30 esu. Plate-shaped OHQ-T and OHQ-TMS single crystal grown by solution growth methods for confirm a linear and nonlinear optical properties. The OHQ-T crystal shows 32 and 2 times higher THz E-field efficiencies at fundamental wavelengths of 1200 and 800 nm and extremely broad THz spectrum with upper cut-off frequency is about 10 THz. |
