Photorefractive effects in photochromic bulk samples

The optically induced change of the refractive index of electro-optic crys tals and glasses has become a very important scientific technique in optical measurements of the photorefractive parameters of media that interact with light.

The photorefractive effect has been studied in photochromic bulk samples. Observations of the decay rate of laser-induced gratings are consistent with the assumption that the speed of the effect is dependent on the relative intensities of the beams that write the grating. A close correlation between diffraction intensities during write and read modes has been observed. The time dependences of the grating build up, decay, and erasure are reported as a function of laser power, wavelength, and write-beam crossing angle.

The results and the observations of those sets of experiments give suggestions for the use of laser-induced gratings in applications such as fibers and other glassy materials.