Two-dimensional optical grating produced on a poly-p-phenylene vinyiene/v₂0₅-gel film by ultrashort pulsed laser radiation

A two-dimensional permanent transmission grating was formed on a novel polymer-gel composite film by ultrashort (˜0.5-ps) and visible (˜602-nm) pulsed laser radiation. With an arrangement of three noncoplanar coherent laser beams, we used two approaches to produce direct formation of a two-dimensional. grating on the film. One approach is to expose the sample twice to different combinations of two beams, and the other is to expose the sample to three laser beams simultaneously. The diffraction patterns and the relative intensity distributions for different order diffraction of the two-dimensional gratings formed on the poly-p-phenylene vinylene/V₂O₅s-gel films are analyzed for the different two-beam combinations and relative orientations among the three laser beams. The total diffraction efficiency for the incident probe laser beam into all the non-zero-order diffraction beams reaches 48%.