Spontaneously Self-Assembled Polar Multilayers With High Second-Order Optical Nonlinearity

Ordered molecular assemblies can lead to materials with extremely high second-order non-linear optical (NLO) properties [1] with applications in technologies such as optoelectronics [2] and permanent magnetism [3]. Although organic molecules with high nonlinearities are well known, it has been difficult to design bulk materials in which the molecules are highly ordered with the same orientation. In this work, we use second harmonic generation (SHG) to determine the second-order nonlinear coefficient (d33) of a spontananeously self-assembled, polar multilayer film (Figure 1) grown by drop casting on a silica substrate. Using ellipsometry to measure film thickness, the average molecular orientation of the chromophores is also determined.