Propagation of laser radiation in phase-sensitive coherent atomic media

Andrey B. Matsko, Irina V. Novikova, George R. Welch

Reabsorption of spontaneously emitted photons, or radiation trapping, is a process that occurs when light interacts with optically thick media. It is shown, both theoretically and experimentally, that this effect in optically thick atomic vapour leads to a decrease in transmission of coherent laser radiation propagating under conditions of electromagnetically induced transparency (EIT). A simple theory is developed taking into account the radiation trapping, which is in a good agreement with the experimental observations and exact numerical simulation. This allows better understanding of the physics of EIT in general, and properties of dense coherent atomic media in particular.

Лукин, Fleischhauer, Alexander S. Zibrov +4 more

Mikhail D. Lukin, Michael Fleischhauer, Alexander S. Zibrov +4 more

Vladimir Mitin, Dmitry I. Sementsov

The analysis of the phenomenon of refraction of electromagnetic waves at the interface between two media suggests that their velocity when passing from one medium to another changes. This chapter describes the basic principles of amplification and discusses the main features of wave propagation in amplifying media. Amplification occurs due to the induced coherent emission by excited atoms under the influence of the field of the electromagnetic wave. The chapter illustrates the attenuation of waves in an absorbing medium by using the Bouguer’s law. Bouguer’s law holds for a wide range of electromagnetic radiation—from radio waves to X-rays and gamma rays. The chapter discusses the main features of the different types of lasers such as solid-state lasers, gas lasers, dye lasers, and semiconductor lasers. It also includes some exercise problems related to the propagation of electromagnetic waves in amplifying media.

Vladimir D Taranukhin, Sergey Y. Ten

A theoretical analysis is made of the propagation of phase-modulated laser pulses in a resonant two-level medium. It is shown that phase modulation results in the appearance of qualitatively new amplification (absorption) regimes. In one of these regimes, trains of ultrashort pulses may be generated at a high repetition frequency. An analysis is also made of the feasibility of compression of amplified pulses.

Eli A. Mishkin