Creating periodic three-dimensional structures by multibeam interference of visible laser

Face-centered cubiclike lattices with periods of 0.9 mum were created by interference of multiple visible laser beams on photosensitive epoxy. Defect-free porous structures were obtained in an area larger than 1 mm within seconds of exposure. The initiating system includes a xanthene dye as a photosensitizer and a diaryliodionium salt as a photoacid generator. An appropriate concentration of triethylamine is added as a neutralizer to eliminate nonzero background caused by partly nonparallel polarization of multiple beams.