Method of multiple scales in quantum optics

Applications of the method of multiple scales to the quantum-optical problems are reviewed. After a preliminary study of applications to the classical and quantum anharmonic oscillator, several examples in the spontaneous emission, resonance fluorescence, and cavity quantum electrodynamics are analyzed. A preliminary account of application of the method to a model of Bose–Einstein condensates is given. A common thread throughout the main body of the review is the stabilization of the wave function and population of a level due to the phase modulation by an external agent.