On-chip single photon emission from an integrated semiconductor quantum dot into a photonic crystal waveguide

International audienceWe investigate the spontaneous emission (SE) of self-assembled InAs quantum dots (QDs) embedded in GaAs ridge waveguides that lay on a low index substrate. In thin enough waveguides, the coupling to the fundamental guided mode is vanishingly small. A pronounced anisotropy in the coupling to non-guided modes is then directly evidenced by normal-incidence photoluminescence polarization measurements. In this regime, a measurement of the QD decay rate reveals a SE inhibition by a factor up to 4. In larger wires, which ensure an optimal transverse confinement of the fundamental guided mode, the decay rate approaches the bulk value. Building on the good agreement with theoretical predictions, we infer from calculations the fraction β of SE coupled to the fundamental guided mode for some important QD excitonic complexes. For a charged exciton (isotropic in plane optical dipole), β reaches 0.61 at maximum for an on-axis QD. In the case of a purely transverse linear optical dipole, β increases up to 0.91. This optimal configuration is achievable through the selective excitation of one of the bright neutral excitons

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confidence: 99%

Quantum dot spontaneous emission control in a ridge waveguide

Stepanov

Delga

Zang

et al. 2015

“…It is difficult to precisely determine the efficiency of the out-coupling grating but the detected count rates in this case are comparable to previous reports where the in-plane emission was collected directly from the exit of the waveguide. 23,29 Calculations of the photonic band structure of an infinite PCWG using the plane-wave expansion method with the same parameters as the one used in the experiment show spectral matching of the emission at 895.1 nm with the fundamental y-polarized propagating mode. 29 Fig .…”

Section: (B) a Tunable Continuous Wave (Cw) Laser Polarized Along Thmentioning

confidence: 99%

“…However, in the emerging field of photonic quantum information technology, it is highly desirable for the integrated quantum emitter to be able to emit highly indistinguishable photons into an on-chip quantum circuit. The integration of QDs in photonic circuits, in particular photonic crystal waveguides (PCWGs), [21][22][23][24][25][26][27] has extended the use of these emitters as integrated in-plane quantum light sources. These systems offer broadband operation, 20 efficiency 23,28 and scalability.…”

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confidence: 99%

Enhanced indistinguishability of in-plane single photons by resonance fluorescence on an integrated quantum dot

Kalliakos

Brody

Bennett

et al. 2016

Self Cite

Integrated quantum light sources in photonic circuits are envisaged as building blocks of future on-chip architectures for quantum logic operations. While semiconductor quantum dots have been proven to be highly efficient emitters of quantum light, their interaction with the host material induces spectral decoherence, which decreases the indistinguishability of the emitted photons and limits their functionality. Here, we show that the indistinguishability of in-plane photons can be greatly enhanced by performing resonance fluorescence on a quantum dot coupled to a photonic crystal waveguide. We find that the resonant optical excitation of an exciton state induces an increase of the emitted single-photon coherence by a factor of 15. Twophoton interference experiments reveal a visibility of 0.80 ± 0.03, which is good agreement with

“…Recent studies have reported the integration of QDs in photonic circuits, in particular photonic crystal waveguides, [16][17][18][19][20][21] which extended the use of these emitters as integrated in-plane quantum light sources.…”

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confidence: 99%

In-plane emission of indistinguishable photons generated by an integrated quantum emitter

Kalliakos

Brody

Schwagmann

et al. 2014

Self Cite

We demonstrate the emission of indistinguishable photons along a semiconductor chip originating from carrier recombination in an InAs quantum dot. The emitter is integrated in the waveguiding region of a photonic crystal structure, allowing for onchip light propagation. We perform a Hong-Ou-Mandel-type of experiment with photons collected from the exit of the waveguide and we observe two-photon interference under continuous wave excitation. Our results pave the way for the integration of quantum emitters in advanced photonic quantum circuits.