Encoding multipolar polarization patterns by optical poling in polymers: towards nonlinear optical memories.

We demonstrate spatially resolved polarization encoding of nonlinear information by all-optical poling of photoisomerizable and nonlinear molecules in polymer films. The second harmonic generation (SHG)polarization responses of the photo-induced patterns are imaged by a nonlinear microscope with 2 microm lateral resolution. The strong SHG dependence to the poling fields polarizations is applied to information encoding, with a potential in high density optical data storage. In addition, the imprinted local nonlinear susceptibilities of multipolar symmetries cannot be deciphered by more traditional one-photon holography techniques.