ABSTRACT
Non-linear optics is the study of intense laser radiation interacting with different materials (organic, semiconductor, glasses, etc.). The non-linear optical (NLO) properties of materials can broadly be classified as second order and third order with a variety of applications for both in the fields of photonics, communications, biological imaging, etc. Recently, with the spate of novel nanomaterials synthesis, the NLO materials have found interesting and robust applications because the non-linearities are enhanced in these classes of materials. This book chapter provides an overview of the recent progress in the NLO studies of a variety of nanomaterials. An introduction is provided for the second- and third-order optical non-linearities at the outset. Various phenomena occurring in different NLO materials as a consequence of second- and third-order non-linearities are discussed. Several nanomaterials studied in the last few years based on second-order and third-order non-linear optical susceptibilities have been highlighted along with their significance and application(s). Though a large number of nanomaterials have been investigated over the last couple of decades, we have confined this review to the third-order NLO studies of (i) metal nanoparticles, (ii) metal nanocomposites and (iii) perovskites. All the NLO coefficients obtained from various studies have been summarized. In the case of second-order NLO materials a few nanomaterials are discussed (both experimental and theoretical works).
