Book excerpt: This book highlights recent advances of optical spatial solitons in photorefractive materials ranging broadly from the coupling, modulation instability, effect of pyroelectricity, and the stability of photorefractive solitons, among other topics. Photorefractive solitons have been at the forefront of research because of their formation at low laser powers and unique saturable nonlinearity present in photorefractive materials which supports solitons in (2+1) D. There has been a spurt in research on photorefractive solitons recently, which has contributed to a greater understanding of the theoretical foundation of photorefractive solitons as also of their various interesting and practical applications. The book elucidates the diversity of photorefractive solitons and provides a good resource for students, researchers, and professionals in the area of nonlinear optics. ​