The plot of the book "Extreme Nonlinear Optics: An Introduction" revolves around the evolution of technology and the need for a personal paradigm to understand the process of developing modern knowledge, which is crucial for the survival of humanity and the unification of people in a warring state. The book explores the rapid emergence of the field of nonlinear optics following the birth of the laser in 1960, and how traditional concepts and approximations no longer apply in this extreme regime. It delves into the novel and unusual effects that arise in this realm, such as frequency doubling in in inverted symmetric materials, high-harmonic generation in gases, and the possibility of achieving attosecond electromagnetic pulses or pulse trains. The book covers a wide range of areas, including solid-state physics, atomic physics, relativistic free electrons in a vacuum, and even the vacuum itself. It provides an introduction to the field of extreme nonlinear optics and its diverse applications, highlighting the importance of understanding this technology for the future of humanity.

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