| 摘要 |
PURPOSE:To provide the title element which has a large nonlinear optical constant, is short in cut-off wavelength and is stable by forming a medium of chromone and the deriv. thereof. CONSTITUTION:The medium is formed of the chromone and the deriv. thereof. The chromone has the structure expressed by formula I. The chromone deriv. has preferably a substituent such as an electrodonating group or electron- attracting group and has further a substituent to prevent having symmetry when crystallized. The representative example thereof is 6-nitrochromone, etc. The nonlinear optical element which is short in the cut-off wavelength, is formed by using the material having nonlinear optical performance and operates efficiently is thereby obtd. |
