Purcell-enhanced single-photon emission from a strain-tunable quantum dot in a cavity-waveguide device

Abstract

On-chip quantum photonics is a promising route toward the implementation of complex photonic architectures on a small footprint. Therefore, different photonic components demonstrated for off-chip operation must be realized in an integrated manner. An essential building block for the realization of this goal is the integration of efficient on-demand single-photon sources within waveguide circuits. Here, we address this challenge by demonstrating the Purcell-enhanced single-photon emission from an In(Ga)As quantum dot coupled to a high-Q cavity-waveguide device. The combination with a piezoelectric actuator further enables the strain-induced emission energy tuning of the quantum dot as well as the cavity mode. We observe wavelength shifts up to 0.85 nm for the quantum dot, with a differential tuning factor of four between emitter and cavity. This allows for the full compensation of the spectral mismatch between a selected quantum dot and the cavity resonance. A nearly twofold enhancement of the spontaneous emission rate is observed at resonance with the on-demand generation of single photons. This demonstration of a strain-tunable emitter in a waveguide-coupled cavity device represents an essential building block for large scale quantum photonic circuits, especially if combined in the future with miniaturization approaches based on recently developed micromachined piezoelectric actuators.

Purcell radiative rate enhancement of label-free proteins with ultraviolet aluminum plasmonics

“…This phenomenon, also called the Purcell effect [1], has been observed in photonic crystal microcavities [2,3] or plasmonic optical nanoantennas [4][5][6][7][8]. The Purcell effect finds its applications for single molecule microscopy [9], single photon sources [10,11], and sub-wavelength lasers [12].…”

Using the Autler-Townes and ac Stark effects to optically tune the frequency of indistinguishable single-photons from an on-demand source

“…We stress that the numbers presented here can be achieved with cavity and QD parameters which have been demonstrated in the literature with semiconductor microcavities [3,4,[81][82][83][84][85][86][87][88][89][90]; the range of Purcell factors shown here (less than 40; cf. a value achieved with a photonic crystal cavity of 43 [86]) can be achieved with (e.g., using dielectric micropillar resonators [3,4,[81][82][83]91]) a linewidth κ of a few hundred µeV (corresponding to Q factors ∼ 10 3 −10 4 ), and a coupling g on the order of (at most) tens of µeV, and the phonon parameter sets we use reflect measured values as discussed in Sec.…”

Accuracy of the quantum regression theorem for photon emission from a quantum dot

“…We demonstrate that the QRT systematically overestimates the phonon impact on the indistinguishability, in particular for standard GaAs QDs relevant for technological applications [39][40][41][42][43][44][45][46]. We show that this is connected to the non-Markovian part of the dynamics.…”