Boost of single-photon emission by perfect coupling of InAs/GaAs quantum dot and micropillar cavity mode

Abstract

We proposed a precise calibration process of Al 0.9 Ga 0.1 As/GaAs DBR micropillar cavity to match the single InAs/GaAs quantum dot (QD) exciton emission and achieve cavity mode resonance and a great enhancement of QD photoluminescence (PL) intensity. Light-matter interaction of single QD in DBR micropillar cavity (Q ∼ 3800) under weak coupling regime was investigated by temperature-tuned PL spectra; a pronounced enhancement (14.6-fold) of QD exciton emission was observed on resonance. The second-order autocorrelation measurement shows g (2) (0)=0.070, and the estimated net count rate before the first objective lens reaches 1.6×10 7 counts/s under continuous wave excitation, indicating highly pure single-photon emission at high count rates.

Single- and Twin-Photons Emitted from Fiber-Coupled Quantum Dots in a Distributed Bragg Reflector Cavity

“…When XX and X are saturated with comparable intensity (i.e., ~40,000 cts per 0.1 s of its PL peak intensity), XX is filtered and its single-photon rate is measured at Si-APDs, 240 kcps, corresponding to an overall XX-X pair rate ~12 Mcps, taking into account Si-APD efficiency (33% at λ~900 nm) and the optical route efficiency. As shown in Figure 2 c, XX becomes dominant under higher pump, with single-photon rate ~21 Mcps as estimated by PL intensity, the same level as a pillar cavity before 1st lens (20~40 Mcps [ 22 ]), reflecting QD at the fiber core center with coupling efficiency > 50%, consistent with simulation [ 23 ]. For QD with a dominant X + and radiative lifetime ~0.2 ns (QD0 in Figure 1 g), the optimal fiber-output single-photon rate will be the same ~20 Mcps.…”

Chip-Scale Quantum Emitters

“…Under a weak coupling regime, the light-matter interaction of single QDs in a DBR micropillar cavity (Q∼3800) was investigated by temperature-tuned PL spectra. In this study, a value of g (2) (0) = 0.070 was demonstrated using the second-order autocorrelation measurement and highly pure single-photon emission at high count rates was indicated by the estimated net count rate before the first objective lens was reached (1.6 × 10 7 counts/s) under continuous wave excitation [45]. A heterogeneous photonic integration platform was developed, allowing direct integration of GaAs waveguides and cavities containing selfassembled InAs/GaAs quantum dots that provide such capabilities in a scalable on-chip implementation [45].…”

“…In this study, a value of g (2) (0) = 0.070 was demonstrated using the second-order autocorrelation measurement and highly pure single-photon emission at high count rates was indicated by the estimated net count rate before the first objective lens was reached (1.6 × 10 7 counts/s) under continuous wave excitation [45]. A heterogeneous photonic integration platform was developed, allowing direct integration of GaAs waveguides and cavities containing selfassembled InAs/GaAs quantum dots that provide such capabilities in a scalable on-chip implementation [45]. In their experiments, a highly efficient optical interface between Si 3 N 4 waveguides and single quantum dots in GaAs geometries was achieved which included quantum dot radiative rate enhancement in microcavities, and a path for reaching the nonperturbative strong-coupling regime [45].…”

“…Besides the development in the preparation of advanced materials such as the QD-based singlephoton emitter employed for experimental demonstration of quantum technologies, the improvement in fabrication techniques also continued. For example, to achieve cavity mode resonance with a great enhancement of QD photoluminescence (PL) intensity, a precise calibration process of an Al 0.9 Ga 0.1 As/GaAs DBR micropillar cavity, which matched the single InAs/GaAs quantum dot (QD) exciton emission, was proposed [45]. Under a weak coupling regime, the light-matter interaction of single QDs in a DBR micropillar cavity (Q∼3800) was investigated by temperature-tuned PL spectra.…”

“…A heterogeneous photonic integration platform was developed, allowing direct integration of GaAs waveguides and cavities containing selfassembled InAs/GaAs quantum dots that provide such capabilities in a scalable on-chip implementation [45]. In their experiments, a highly efficient optical interface between Si 3 N 4 waveguides and single quantum dots in GaAs geometries was achieved which included quantum dot radiative rate enhancement in microcavities, and a path for reaching the nonperturbative strong-coupling regime [45]. Davanco et al [46] indicated that robust implementation of single-photon sources can be achieved through the use of systems that provide both strong light-matter interactions and a low-loss interface between emitters and optical fields (Figure 7).…”