Non-classical States of Light After Strong-Laser Field Processes in Atoms

The invention of the laser by T. H. Maiman in 1960 led to significant advancements in science and technology that profoundly influenced the latter half of the 20th century and beyond, revolutionizing numerous fields. The widespread adoption of lasers became feasible due to the availability of a wide range of laser sources, each differing in intensity, frequency, beam spatial distribution, pulse duration and other properties. Consequently, laser technology has been effectively tailored to meet the specific requirements of various scientific communities. Nowadays, it is possible to create laser sources with intensities high enough to compete with the atomic internal forces, firmly consolidating strong-field physics and attosecond science as well-established fields of Physics. This chapter, delves into the quantum optical description of strong-field physics processes, highlighting how these could lead to non-classical states of light.