All-optical gel memory.

We have studied the behavior of organic molecules (Rhodamine 640) that are encaged in a matrix synthesized by the sol-gel process. By applying a strong optical-polarized electric field, we can control the alignment of the molecules within the sample and locally create a birefringent effect. Using this sample in a Kerr experiment, we obtained a transmission ratio of 6%. Since the birefringent effect lasts at least several days, this type of sample could be used in an optical process for storage of information. Moreover, we show that such information can be deleted and rewritten repetitively.