Figure 4: Bright single-photon emission of tailored nanowire waveguides. | Nature Communications

Figure 4: Bright single-photon emission of tailored nanowire waveguides.

From: Bright single-photon sources in bottom-up tailored nanowires

Figure 4

(a) Typical power dependence of single quantum dot in tailored nanowire waveguide under pulsed laser excitation. The PL spectra are offset for clarity. (b) Integrated counts of exciton (X), biexciton (XX), and charged exciton (X) from (a) as a function of increasing excitation power. Remarkably, the X line saturates at values as high as 236,000 counts per second measured on the CCD detector, resulting in a photon-collection efficiency of 30%. Accounting for competition between recombination of X and X, we estimate an η for the nanowire waveguide of 42%. We note that the calculated collection efficiencies are only valid at quantum dot saturation where the generation efficiency is maximum. (c) Second-order correlation function, g(2)(τ), of single X line. The anti-bunching dip below 0.5 is characteristic of a single-photon emitter. Accounting for the finite time response of our single-photon detectors, we obtain g(2)(0) of 0.12 and X lifetime of 1.7 ns±0.1 ns.

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