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High Purcell factor generation of indistinguishable on-chip single photons


On-chip single-photon sources are key components for integrated photonic quantum technologies. Semiconductor quantum dots can exhibit near-ideal single-photon emission, but this can be significantly degraded in on-chip geometries owing to nearby etched surfaces. A long-proposed solution to improve the indistinguishablility is to use the Purcell effect to reduce the radiative lifetime. However, until now only modest Purcell enhancements have been observed. Here we use pulsed resonant excitation to eliminate slow relaxation paths, revealing a highly Purcell-shortened radiative lifetime (22.7 ps) in a waveguide-coupled quantum dot–photonic crystal cavity system. This leads to near-lifetime-limited single-photon emission that retains high indistinguishablility (93.9%) on a timescale in which 20 photons may be emitted. Nearly background-free pulsed resonance fluorescence is achieved under π-pulse excitation, enabling demonstration of an on-chip, on-demand single-photon source with very high potential repetition rates.

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Fig. 1: Details of the waveguide-coupled QD-H1 PhCC system.
Fig. 2: The DPRF technique.
Fig. 3: Plot of the ratio of the coherently scattered laser photons (IRRS) to the total scatter (Itotal = IRRS + ISE) as a function of Rabi frequency and CW excitation power.
Fig. 4: Second-order correlation measurements of the waveguide-coupled QD emission under resonant π-pulse excitation.


  1. 1.

    Aaronson, S. & Arkhipov, A. The computational complexity of linear optics. In 43rd Annual ACM Symposium on Theory of Computing, STOC ’11 333–342 (ACM Press, New York, 2011).

  2. 2.

    Tillmann, M. et al. Experimental boson sampling. Nat. Photon. 7, 540–544 (2013).

    Article  Google Scholar 

  3. 3.

    Broome, M. A. et al. Photonic boson sampling in a tunable circuit. Science 339, 794–798 (2013).

    Article  Google Scholar 

  4. 4.

    Wang, H. et al. High-efficiency multiphoton boson sampling. Nat. Photon. 11, 361–365 (2017).

    Article  Google Scholar 

  5. 5.

    Loredo, J. C. et al. Boson sampling with single-photon Fock states from a bright solid-state source. Phys. Rev. Lett. 118, 130503 (2017).

    Article  Google Scholar 

  6. 6.

    Silverstone, J. W. et al. On-chip quantum interference between silicon photon-pair sources. Nat. Photon. 8, 104–108 (2014).

    Article  Google Scholar 

  7. 7.

    Laucht, A. et al. A waveguide-coupled on-chip single-photon source. Phys. Rev. X 2, 11014 (2012).

    Google Scholar 

  8. 8.

    Lund-Hansen, T. et al. Experimental realization of highly efficient broadband coupling of single quantum dots to a photonic crystal waveguide. Phys. Rev. Lett. 101, 113903 (2008).

    Article  Google Scholar 

  9. 9.

    Makhonin, M. N. et al. Waveguide coupled resonance fluorescence from on-chip quantum emitter. Nano. Lett. 14, 6997–7002 (2014).

    Article  Google Scholar 

  10. 10.

    Reithmaier, G. et al. On-chip generation, routing, and detection of resonance fluorescence. Nano. Lett. 15, 5208–5213 (2015).

    Article  Google Scholar 

  11. 11.

    Hausmann, B. J. M. et al. Integrated diamond networks for quantum nanophotonics. Nano. Lett. 12, 1578–1582 (2012).

    Article  Google Scholar 

  12. 12.

    Sipahigil, A. et al. An integrated diamond nanophotonics platform for quantum optical networks. Science 354, 847–850 (2016).

    Article  Google Scholar 

  13. 13.

    Santori, C., Fattal, D., Vucković, J., Solomon, G. S. & Yamamoto, Y. Indistinguishable photons from a single-photon device. Nature 419, 594–597 (2002).

    Article  Google Scholar 

  14. 14.

    He, Y.-M. et al. On-demand semiconductor single-photon source with near-unity indistinguishability. Nat. Nanotech. 8, 213–217 (2013).

    Article  Google Scholar 

  15. 15.

    Somaschi, N. et al. Near-optimal single-photon sources in the solid state. Nat. Photon. 10, 340–345 (2016).

    Article  Google Scholar 

  16. 16.

    Ding, X. et al. On-demand single photons with high extraction efficiency and near-unity indistinguishability from a resonantly driven quantum dot in a micropillar. Phys. Rev. Lett. 116, 020401 (2016).

    Article  Google Scholar 

  17. 17.

    Wang, H. et al. Near transform-limited single photons from an efficient solid-state quantum emitter. Phys. Rev. Lett. 116, 213601 (2016).

    Article  Google Scholar 

  18. 18.

    Dietrich, C. P., Fiore, A., Thompson, M. G., Kamp, M. & Höfling, S. GaAs integrated quantum photonics: Towards compact and multi-functional quantum photonic integrated circuits. Laser & Photonics Rev. 10, 870–894 (2016).

    Article  Google Scholar 

  19. 19.

    Liu, J. et al. Single self-assembledÿInAs/GaAs quantum dots in photonic nanostructures: The role of nanofabrication. Phys. Rev. Appl. 9, 064019 (2018).

    Article  Google Scholar 

  20. 20.

    Kalliakos, S. et al. Enhanced indistinguishability of in-plane single photons by resonance fluorescence on an integrated quantum dot. Appl. Phys. Lett. 109, 151112 (2016).

    Article  Google Scholar 

  21. 21.

    Kiraz, A., Atatüre, M. & Imamoğlu, A. Quantum-dot single-photon sources: Prospects for applications in linear optics quantum-information processing. Phys. Rev. A. 69, 032305 (2004).

    Article  Google Scholar 

  22. 22.

    Purcell, E. Spontaneous emission probabilities at radio frequencies. Phys. Rev. 69, 681 (1946).

    Article  Google Scholar 

  23. 23.

    Englund, D. et al. Controlling the spontaneous emission rate of single quantum dots in a two-dimensional photonic crystal. Phys. Rev. Lett. 95, 13904 (2005).

    Article  Google Scholar 

  24. 24.

    Ota, Y. et al. Enhanced photon emission and absorption of single quantum dot in resonance with two modes in photonic crystal nanocavity. Appl. Phys. Lett. 93, 183114 (2008).

    Article  Google Scholar 

  25. 25.

    Kress, A. et al. Manipulation of the spontaneous emission dynamics of quantum dots in two-dimensional photonic crystals. Phys. Rev. B 71, 241304 (2005).

    Article  Google Scholar 

  26. 26.

    Badolato, A. et al. Deterministic coupling of single quantum dots to single nanocavity modes. Science 308, 1158–1161 (2005).

    Article  Google Scholar 

  27. 27.

    Happ, T. D. et al. Enhanced light emission of InxGa1−xAs quantum dots in a two-dimensional photonic-crystal defect microcavity. Phys. Rev. B 66, 41303 (2002).

    Article  Google Scholar 

  28. 28.

    Kim, J.-H., Cai, T., Richardson, C. J. K., Leavitt, R. P. & Waks, E. Two-photon interference from a bright single-photon source at telecom wavelengths. Optica 3, 577–584 (2016).

    Article  Google Scholar 

  29. 29.

    Laurent, S. et al. Indistinguishable single photons from a single-quantum dot in a two-dimensional photonic crystal cavity. Appl. Phys. Lett. 87, 163107 (2005).

    Article  Google Scholar 

  30. 30.

    Bentham, C. et al. On-chip electrically controlled routing of photons from a single quantum dot. Appl. Phys. Lett. 106, 221101 (2015).

    Article  Google Scholar 

  31. 31.

    Coles, R. J. et al. Waveguide-coupled photonic crystal cavity for quantum dot spin readout. Opt. Express 22, 2376–2385 (2014).

    Article  Google Scholar 

  32. 32.

    Reithmaier, G. et al. A carrier relaxation bottleneck probed in single InGaAs quantum dots using integrated superconducting single photon detectors. Appl. Phys. Lett. 105, 081107 (2014).

    Article  Google Scholar 

  33. 33.

    Zibik, E. A. et al. Long lifetimes of quantum-dot inter-sublevel transitions in the terahertz range. Nat. Mater. 8, 803–807 (2009).

    Article  Google Scholar 

  34. 34.

    Berstermann, T. et al. Systematic study of carrier correlations in the electron–hole recombination dynamics of quantum dots. Phys. Rev. B 76, 165318 (2007).

    Article  Google Scholar 

  35. 35.

    Ramsay, A. J. et al. Phonon-induced Rabi-frequency renormalization of optically driven single InGaAs/GaAs quantum dots. Phys. Rev. Lett. 105, 177402 (2010).

    Article  Google Scholar 

  36. 36.

    Melloni, A. et al. Tunable delay lines in silicon photonics: Coupled resonators and photonic crystals, a comparison. IEEE Photonics J. 2, 181–194 (2010).

    Article  Google Scholar 

  37. 37.

    Matthiesen, C., Vamivakas, A. N. & Atatüre, M. Sub-natural linewidth single photons from a quantum dot. Phys. Rev. Lett. 108, 093602 (2012).

    Article  Google Scholar 

  38. 38.

    Proux, R. et al. Measuring the photon coalescence time window in the continuous-wave regime for resonantly driven semiconductor quantum dots. Phys. Rev. Lett. 114, 067401 (2015).

    Article  Google Scholar 

  39. 39.

    Bennett, A. J. et al. Cavity-enhanced coherent light scattering from a quantum dot. Sci. Adv. 2, e1501256 (2016).

    Article  Google Scholar 

  40. 40.

    Iles-Smith, J., McCutcheon, D. P. S., Nazir, A. & Mørk, J. Phonon scattering inhibits simultaneous near-unity efficiency and indistinguishability in semiconductor single-photon sources. Nat. Photon. 11, 521–526 (2017).

    Article  Google Scholar 

  41. 41.

    Thoma, A. et al. Exploring dephasing of a solid-state quantum emitter via time- and temperature-dependent Hong–Ou–Mandel experiments. Phys. Rev. Lett. 116, 033601 (2016).

    Article  Google Scholar 

  42. 42.

    Wang, C. F. et al. Optical properties of single InAs quantum dots in close proximity to surfaces. Appl. Phys. Lett. 85, 3423–3425 (2004).

    Article  Google Scholar 

  43. 43.

    Loredo, J. C. et al. Scalable performance in solid-state single-photon sources. Optica 3, 433–440 (2016).

    Article  Google Scholar 

  44. 44.

    Löbl, M. C. et al. Narrow optical linewidths and spin pumping on charge-tunable close-to-surface self-assembled quantum dots in an ultrathin diode. Phys. Rev. B 96, 165440 (2017).

    Article  Google Scholar 

  45. 45.

    Pernice, W. et al. High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits. Nat. Commun. 3, 1325 (2012).

    Article  Google Scholar 

  46. 46.

    Fan, S., Kocaba¸s, E. & Shen, J.-T. Input–output formalism for few-photon transport in one-dimensional nanophotonic waveguides coupled to a qubit. Phys. Rev. A. 82, 063821 (2010).

    Article  Google Scholar 

  47. 47.

    Lindner, N. H. & Rudolph, T. Proposal for pulsed on-demand sources of photonic cluster state strings. Phys. Rev. Lett. 103, 113602 (2009).

    Article  Google Scholar 

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This work was funded by the EPSRC (UK) Programme Grants EP/J007544/1 and EP/N031776/1. The authors thank A. Ul-Haq, J. Iles-Smith, G. Buonaiuto, R. Kirkwood and S. Hughes for helpful discussions.

Author information




F.L. and A.J.B. designed and oversaw the experimental program. A.J.B., L.M.P.P.M. and F.L. developed the DPRF technique and carried out the measurements. J.O’H., L.M.P.P.M., A.J.B. and F.L. performed the SPAD lifetime measurements. J.O’H. and A.J.B. performed the RRS measurements with additional input from N.P.. A.J.B., J.O’H., L.M.P.P.M., F.L. and C.L.P. performed the pulsed correlation measurements. J.O’H. performed the master equation simulations of the system. R.J.C. designed and simulated the photonic structures. C.B. and I.E.I. performed initial characterization of the sample. E.C. grew the quantum dot wafer whilst B.R. fabricated the photonic nanostructures and processed the QD wafer into diodes with assistance from C.B.. L.R.W, I.E.I., M.S.S and A.M.F. provided supervision and expertise. F.L., A.J.B., J.O’H. and A.M.F. wrote the manuscript with input from all authors.

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Correspondence to Alistair J. Brash.

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Supplementary Text, Supplementary Figures 1–12

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Liu, F., Brash, A.J., O’Hara, J. et al. High Purcell factor generation of indistinguishable on-chip single photons. Nature Nanotech 13, 835–840 (2018).

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