Quantum optics: Difference between revisions

{{Short description|Sub-field of quantum physics and optics}}

{{Redirect|Quantum electronics|the journal|Quantum Electronics (journal)}}

==History==

Light propagating in a vacuum has its [[energy]] and [[momentum]] quantized according to an integer number of particles known as [[photons]]. Quantum optics studies the nature and effects of light as quantized photons. The first major development leading to that understanding was the correct modeling of the [[blackbody radiation]] spectrum by [[Max Planck]] in 1899 under the hypothesis of light being emitted in discrete units of energy. The [[photoelectric effect]] was further evidence of this quantization as explained by [[Albert Einstein]] in a 1905 paper, a discovery for which he was to be awarded the [[Nobel Prize]] in 1921. [[Niels Bohr]] showed that the hypothesis of optical radiation being quantized corresponded to his theory of the [[quantized energy levels of atoms]], and the [[spectrum]] of [[Gas-discharge lamp|discharge emission]] from [[hydrogen]] in particular. The understanding of the interaction between light and [[matter]] following these developments was crucial for the development of [[quantum mechanics]] as a whole. However, the subfields of quantum mechanics dealing with matter-light interaction were principally regarded as research into matter rather than into light; hence one rather spoke of [[atom physics]] and [[quantum electronics]] in 1960. [[Laser science]]—i.e., research into principles, design and application of these devices—became an important field, and the quantum mechanics underlying the laser's principles was studied now with more emphasis on the properties of light{{dubious|date=May 2013}}, and the name ''quantum optics'' became customary.