The main theme of this book is the study of the three-dimensional (3D) propagation dynamics of spatio-temporal wave packets. The Airy-Bessel wave packet is the main wave packet to be studied in the thesis. Other wave packets such as Airy-Airy-Airy and dual-Airy-Airy-rings are also investigated. An Airy-Bessel wave packet has been studied as a ``linear light bullet since it can propagate without dispersion or diffraction in the linear regime. An Airy-Airy-Airy wave packet also belongs to the family of ``linear light bullets. It has been studied both in the linear and the nonlinear regime. A...