Key points are not available for this paper at this time.
Exhaustive, if not exhausting, is the appropriate epithet for this book; the subject has come a long way since Bloembergen's modest monograph of 20 years ago and the author of this book has been active in the field for most of that period. Nonlinear optical effects depend on the presence of a material medium and they are due to nonlinear variation of the polarisability of the medium at high field strengths.
W.T. Welford (Mon,) studied this question.