| 摘要 |
PURPOSE:To have large optical nonlinearity for wavelength conversion of a semiconductor laser and to have visible absorption on a short wavelength side with a transmission type by forming an org. nonlinear optical material of a specific compd. having an acceptor-type group and halogen. CONSTITUTION:This org. nonlinear optical material consists of formula I, where A denotes the acceptor-type group and X denotes the halogen. The halogen has the specific property that the halogen is of the acceptor type with respect to a sigma electron and of a donor type with respect to a pi electron. The dipole moment does not increase in the case of this component and since the flexibility of the pi electron which is the origin of the optical nonlinearity of the org. material, the nonlinearity of the molecular light does not have to be smaller than in the case of introducing the donor-type group strong to a benzene deriv. In addition, the visible absorption is nearer the short wavelength side than the known benzene deriv. and, therefore, the problems such as deterioration of the compd. and the degradation in conversion efficiency by the reabsorption of a second harmonic wave due not arise even in the case of subjecting the semiconductor laser light to wavelength conversion. The large optical nonlinearity and the visible absorption on the short wavelength side are thereby provided to this material and the wavelength conversion of the semiconductor laser with the transmission type is enabled. |
