The in plane molecular alignment in Y type Langmuir Blodgett multilayers of a hemicyanine dye (DAEP) interleaved with inert material arachidic acid (AA) due to dipping induction and interlayer interactions was demonstrated by polarized UV visible absorption and rotation angle second harmonic generation techniques. We gave the first direct evidence for a super quadratic enancement of the second harmonic intensities with increasing film thickness due to the additional in plane polarization.