Multiphoton-induced two-dimensional microstructures in dye-doped bulk materials by four-beam interference of femtosecond pulses

Multiphoton-induced two-dimensional periodic microstructures were fabricated in dye-doped bulk transparent materials by four-beam interference of femtosecond pulses at a wavelength of 800 nm. Observations of optical microscopy show that two-dimensional microstructures are realized in the samples through nonresonant absorption process. The photoinduced refractive index modulation, resulted from the multiphoton-induced photodecomposition, is responsible for the periodic microstructures. These results suggest that this method can be applied to a wide variety of transparent materials and that the materials co-doped with different dyes and with photoinduced microstructure may be possible to make the distributed feedback lasers with novel properties.