Device for generating individual photons
A device for generating individual photons with energy E includes quantum emitters, having at least one determined transition with the energy E from an energy level N* to a lower energy level N 1 . The emitters are near a propagation path running from first to second regions. The device also includes at least one light source to output light, for propagation along the path. The light has the energy E for resonant excitation of the energy level N*. The emitters are arranged so that optionally exactly Z emitters are illuminated, forming an optical thickness τ>0 for the light along the path. The number Z lies in a range of Z 0 ±10% and Z 0 is a number at which a maximum destructive interference in the second region occurs between a two-photon component of the light scattered on the ZO emitters and a two-photon component of the non-scattered light.
1. A device for generating single photons with an energy E, comprising a plurality of quantum emitters which have at least one determined transition with the energy E from an energy level N* to a lower energy level N 1 ,
wherein the quantum emitters are arranged in the region of a propagation path extending from a first region to a second region,
the device further comprising at least one light source for emitting light for propagation along the propagation path,
wherein the light has the energy E for resonantly exciting the energy level N*,
wherein the quantum emitters are arranged in such a way that only exactly Z quantum emitters are illuminated, which form an optical thickness T>0 for the light along the propagation path, the number Z lying in a range Z 0 ±10%, and
wherein Z 0 is that number at which, in the second region a destructive interference between a two-photon component of the light that is scattered at these Z 0 quantum emitters and a two-photon component of the light that is not scattered is at a maximum.
2. The device according to claim 1 , wherein the light source is a laser source.
3. The device according to claim 2 , wherein the light source comprises at least one laser diode.
4. The device according to claim 1 , wherein the quantum emitters comprise atoms and/or ions and/or molecules and/or quantum dots and/or defects in crystal structures.
5. The device according to claim 1 , wherein at least one optical element is provided for defining the propagation path.
6. The device according to claim 1 ,
wherein an optical waveguide comprising a waveguide core is provided for guiding the light,
wherein the Z quantum emitters are arranged in a near field, and
wherein the near field comprises the electromagnetic field of the light in the waveguide core and outside the waveguide core.
7. The device according to claim 6 , wherein the waveguide is designed as an optical fiber.
8. The device according to claim 6 , wherein the waveguide core is arranged on a substrate.
9. The device according to claim 8 , wherein the waveguide core is at least in sections sunk into the substrate.
10. The device according to claim 1 , wherein a photonic crystal fiber having a hollow core is provided for guiding the light.
11. The device according to claim 10 , wherein the quantum emitters are arranged in the hollow core.
12. The device according to claim 1 ,
wherein a crystal is arranged in the propagation path, and
wherein the Z quantum emitters are formed by crystal defects in the crystal.
13. The device according to claim 12 ,
wherein the Z quantum emitters are formed by dopant atoms,
wherein a material of the crystal comprises silicon, and
wherein the dopant atoms comprise boron atoms or phosphorus atoms.
14. The device according to claim 12 , wherein the Z quantum emitters are formed by impurity atoms and/or vacancies.
15. The device according to claim 14 , wherein the Z quantum emitters are formed by dopant atoms.
16. The device according to claim 1 , wherein the quantum emitters are in gas form in the region of the propagation path.
17. The device according to claim 16 ,
wherein the quantum emitters have a further transition with the energy E′ from the energy level N 1 to a lower energy level N 0 ,
wherein at least one further light source is provided for emitting further light, and
wherein the further light has the energy E′, in order to resonantly excite the energy level N 1 at quantum emitters and then to excite the energy level N* with the light of energy E at Z of these quantum emitters.
18. The device according to claim 17 , wherein the at least one further light source is provided for emitting further light provides light of a further light mode.
19. The device according to claim 16 , wherein the quantum emitters comprise lithium atoms and/or sodium atoms and/or potassium atoms and/or rubidium atoms and/or cesium atoms.
20. The device according to claim 1 , wherein the device comprises the at least one light source for emitting light of one light mode.