Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling

Abstract

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres.

Controlling the properties of single photon emitters via the Purcell effect

“…In the limit, if the background photon emission is much weaker than QD emission, the value g (2) (0) = 0 should be ideally reached. A similar behavior has been reported 19,28 where the relative weight of the background recombination contribution to the cavity emission decreases with decreasing detuning.…”

Two-photon interference from a bright single-photon source at telecom wavelengths

“…We could improve the indistinguishability using quasi-resonant [14,39,49] or resonant excitation schemes [16][17][18]50], which have already been demonstrated to improve indistinguishability at near infrared wavelengths. We note that InAs/InP quantum dots could potentially emit single photons at 1.5 μm [27,30], so our device and approach could be readily extended to this wavelength range for generating single photons at the c-band. Ultimately, our results show that InAs/InP quantum dots are promising candidates for producing indistinguishable photons for long distance quantum information applications [55,56].…”

“…Quantum dots in III-V semiconductors are particularly promising quantum emitters that generate single photons with high indistinguishability at nearinfrared wavelengths [13][14][15][16][17][18], and are also compatible with electrical injection [19,20] and integration with nanophotonic structures [21][22][23][24]. A number of works have extended the emission of III-V quantum dots to telecom wavelengths by optimizing materials and growth parameters [25][26][27][28][29][30][31]. However, an on-demand source of indistinguishable single photons remains an outstanding challenge at telecom wavelength.…”

Two-Photon Interference from the Far-Field Emission of Chip-Integrated Cavity-Coupled Emitters

“…We couple multiple InAs/InP quantum dots that serve as efficient single photon sources 22,29,30 to independent photonic crystal cavities fabricated in close proximity on the same chip. In order to match the cavity resonances and compensate for fabrication errors, we utilize combination of nitrogen gas deposition and local thermal evaporation.…”