I need 3 pages that explain photo refractive materials. also, I attached an image that mentioned on this title to be more clear for you.
Photo-refractive materials:
Preface to the photo-refractive property:
Photo refractive materials:
Typical wave interactions in the photo-refractive materials:
![1926_unnamed.jpg](https://secure.tutorsglobe.com/CMSImages/1926_unnamed.jpg)