Figure 1

(a) An illustration of our device. (b) Arrangement of the Michelson interferometer used to measure the coherence time. The emission is divided and recombined at different points on a nonpolarizing beam splitter. (c) Mach-Zehnder interferometer for measuring two-photon interference. Horizontally polarized photons are selected using a polarizing beam splitter and a half-wave plate (${\mathrm{HWP}}_1$) aligns the polarization to the axis of the polarization-maintaining single-mode fiber. A monochromator (omitted for clarity) located between ${\mathrm{HWP}}_1$ and the lens is used to filter the emission. The emission is then coupled into the fiber and split at the first coupler $C_1$. The two arms can be made distinguishable or indistinguishable by rotating ${\mathrm{HWP}}_2$. For indistinguishable photons interference occurs at the final coupler $C_2$, resulting in a suppression of coincident counts at the two avalanche photodiode detectors $D_1$ and $D_2$.Reuse & Permissions

Figure 2

(a) Electroluminescence spectra showing the two charged exciton states. (b) Typical visibility plots taken with an injection current of $200\mu \mathrm{A}$. Solid circles correspond to line $A$ emitting at 946.3 nm and open circles to line $B$ emitting at 946.8 nm. (c) Measurements of the coherence time ${\tau }_c$ as a function of current. The black lines are the theoretical fits.Reuse & Permissions

Figure 3

Hanbury Brown–Twiss and two-photon interference results. (a) The measured system response (solid line) and its Gaussian approximation with FWHM $\delta t=428\mathrm{ps}$ (dashed line). In (b) to (e) dashed lines show ideal curves without detection system limitation and bold lines model the effect of finite system response. (b) $g^{(2)}(\tau )$. (c) $g_{\parallel }^{(2)}(\tau )$; dotted line indicates the classical limit. (d) $g_{\perp }^{(2)}(\tau )$. (e) Detailed plot of (c). (f) Two-photon interference visibility. (g) Variation in $V_{\mathrm{HOM}}$ with system resolution $\delta t$ and coherence time ${\tau }_c$. The bold lines correspond to our experimental conditions.Reuse & Permissions