A single quantum emitter single photon source produces a single photon stream and includes: a single-mode excitation waveguide that receives a pump light, propagates pump light as resonant excitation light, and produces evanescent excitation light; a separation gap between single-mode excitation waveguide and a multi-mode intermediate waveguide; a multi-mode intermediate waveguide that: includes a single quantum emitter, evanescently receives the evanescent excitation light from the single-mode excitation waveguide, propagates the evanescent excitation light as resonant excitation light, and subjects the single quantum emitter to the resonant excitation light such that the single quantum emitter produces emitted single photons; and a single-mode output waveguide that receives the emitted single photons from the multi-mode intermediate waveguide and propagates the emitted single photons as an emitted single photon stream.
The invention is an integrated photonic device which allows production of a pure stream of on-chip waveguide-bound indistinguishable single-photons from the resonance fluorescence of a single quantum emitter embedded in a multimode on-chip waveguide, for which the quantum emitter is excited by on-chip waveguide-bound resonant laser light.
There are currently no commercial products that involve on-demand production of single-photons in on-chip waveguides. In the laboratory, however, resonant optical excitation of single quantum emitters in waveguides, for on-demand generation of indistinguishable waveguided single-photons, is typically done through a free-space optical beam perpendicular to the chip surface, from an off-chip laser source. Furthermore, the emitted single-photons are emitted into the same waveguide in which the quantum emitter is embedded.
While in the new scheme some undesirable amount of the excitation laser power may still leak into the single-photon output waveguide, the level of purity of the single-photon stream may be more carefully optimized, as compared to the free-space excitation mode, by controlling the degree of coupling between modes in the SM and MM waveguides, and the emitter-waveguide coupling -factors, which can be done by simple modifications to the on-chip waveguides’ dimensions.
A further advantage of this scheme is that it can be more simply integrated with on-chip, waveguide-coupled lasers that may act as the excitation source to the quantum emitter.