Colloquium: Quantum optics of intense light--matter interaction

TL;DR

This paper reviews the development of quantum optics in intense light-matter interactions, highlighting how fully quantized models are advancing fundamental understanding and enabling new technological applications in high-field physics and attosecond science.

Contribution

It discusses recent progress in fully quantum descriptions of intense light-matter interactions, bridging quantum optics with strong-field physics and ultrafast science.

Findings

Quantum models reveal new phenomena in high harmonic generation.

Fully quantized descriptions enable novel quantum technologies.

Advances facilitate deeper understanding of strong-field processes.

Abstract

Intense light-matter interaction largely relies on the use of high-power light sources, creating fields comparable to, or even stronger than, the field keeping the electrons bound in atoms. Under such conditions, the interaction induces highly nonlinear processes such as high harmonic generation, in which the low-frequency photons of a driving laser field are upconverted into higher-frequency photons. These processes have enabled numerous groundbreaking advances in atomic, molecular, and optical physics, and they form the foundation of attosecond science. Until recently, however, such processes were typically described using semi-classical approximations, since the quantum properties of the light field were not required to explain the observables. This has changed in the recent past. Ongoing theoretical and experimental advances show that fully quantized descriptions of intense light-matter interactions, which explicitly incorporate the quantum nature of the light field, open new avenues for both fundamental research and technological applications at the fully quantized level. These advances emerge from the convergence of quantum optics with strong-field physics and ultrafast science. Together, they have given rise to the field of quantum optics and quantum electrodynamics of strong-field processes.