FORM BIREFRINGENCE OF VOLUME GRATINGS IN PHOTOPOLYMERS

We investigate experimentally the form birefringence due to photoinduc ed one- and two-dimensional volume index gratings in DuPont photopolym ers. Experimental results on the dispersion of the form birefringence versus the illumination wavelength and the grating period for one-dime nsional gratings are presented. We also investigate the form birefring ence due to two-dimensional volume gratings. Positive form birefringen ce and biaxial form birefringence can be obtained by recording two vol ume gratings with different grating wave vectors. (C) 1996 American In stitute of Physics.