RP Photonics logo
VL logo part of the
Virtual
Library

Encyclopedia of Laser Physics and Technology

Rabi Oscillations

previous  |  next  |  feedback

Definition: oscillations of level populations (or quantum mechanical probability amplitudes) under the influence of an incident light field

If light interacts with a two-level system (e.g. an atom or ion with a ground state and an excited state), this can lead to a periodic exchange of energy between the light field and the two-level system. Such oscillations, which are called Rabi oscillations (with reference to the Nobel Prize winner Isidor Isaac Rabi), are associated with oscillations of the quantum mechanical expectation values of level populations and photon numbers. They can be interpreted as a periodic change between absorption and stimulated emission of photons, and can be modeled using the Bloch vector formalism. A competing process, which can prevent the observation of these oscillations, is spontaneous emission.

The angular frequency of the Rabi oscillations (2π times the number of Rabi cycles per second) is called the Rabi frequency. It is proportional to the amplitude (not the optical intensity) of the light field and to the dipole moment of the level transition.

When a solid-state gain medium is optically pumped, Rabi oscillations usually cannot be observed, since the upper and lower states actually consist of Stark level manifolds and coherence is quickly destroyed by phonons. Further, inhomogeneous broadening may occur, and the optical intensities are usually not spatially uniform.

See also: quantum optics, gain media, coherence, optical pumping

Categories: physical foundations, quantum optics


cover of print encyclopedia

Since October 2008, the Encyclopedia of Laser Physics and Technology is also available in the form of a two-volume book. Maybe you would enjoy reading it also in that form! The print version has a carefully designed layout and can be considered a must-have for any institute library, laser research group, or laser company.

You may order the print version via Wiley-VCH.

arrow
Home New articles Spotlight Feedback Advertising
Categories Search Quiz Glossary Page hits
R

This encyclopedia is provided by
RP Photonics Consulting GmbH.

You can get technical consulting from the author, Dr. Rüdiger Paschotta.

Onefive logo

Onefive

Low-noise
femtosecond,
picosecond,
and tunable single-frequency lasers for OEM and R&D applications.

RP Fiber Power 2.0

RP Fiber Power

This software is a powerful tool for designing fiber amplifiers and fiber lasers.
See the comprehensive description!

A.L.S. logo

A.L.S. GmbH

Picosecond laser diodes
<30 ps, 375 – 1600 nm, >1 Wp, single shot – 120 MHz

EKSMA logo

EKSMA Optics

Supplier of laser components, including optics, laser crystals and optomechanics.

Your Advertisement at This Place

will be seen by many thousands of visitors per month. These banners receive far over 100'000 page hits per month. Check the details.