Describing High-Order Harmonic Generation Using Quantum Optical Models

Optical generation of high-order harmonics is a prototypical example nonlinear light–matter interactions in the high-field regime. Quantum optical effects have recently been demonstrated to significant influence on this phenomenon. These findings underline importance understanding dynamics quantized electromagnetic field during harmonic generation. In following, we discuss challenges that are related theoretical description process and summarize results were obtained using high-field, multimode generalization well-known quantum models based concept two-level atom.