Optical phase conjugation
The optical phase conjugation is an effect of nonlinear optics .
During phase conjugation, a coherent, monochromatic , i.e. single-colored, light beam creates a "time-inverse" beam, which propagates in the opposite direction to the original beam and is called a "phase conjugated beam" to this. In this beam, the wave vector points exactly in the opposite direction from that of the output beam. The name comes from the mathematical description of the situation using monochromatic plane waves .
Here the amplitude of the wave is obtained and only the phase is conjugated . A divergent light beam is reflected at the phase conjugate mirror as a convergent beam, in contrast to normal reflection, in which it diverges further. Furthermore, it does not obey the law of reflection of an ordinary mirror, but runs back into itself.
Optical phase conjugation is used in the form of phase conjugating mirrors that reflect each incoming light beam exactly into itself. The properties of these optical elements differ significantly from conventional mirrors . The materials must have a high third-order dielectric susceptibility . The possible applications of phase conjugating mirrors range from optical resonators , signal transmission , pattern recognition to laser-induced nuclear fusion .
The technical realization of phase-conjugating mirrors is mainly done through four-wave mixing .
Optical phase conjugation was introduced in Russia in 1972 by Boris Jakowlewitsch Seldowitsch . Robert Hellwarth introduced the four-shaft mix in 1977.
Further information
- Boris Zeldovich , Nikolai Pilipetskii, Vladimir Shkunov Principles of phase conjugation , Springer Series in Optical Sciences, Volume 42, 1985
- Steven Lehar: An Intuitive Explanation of Phase Conjugation. (English).
- Robert W. Boyd: Nonlinear Optics . 3. Edition. Academic Press, New York 2008, ISBN 978-0-12-369470-6 .