Figure 4

Characterization of single-photon collection from crossed-arc waveguides.

(a) Wide-field reflection-mode optical microscope image under white-light illumination showing light coupled in and out of the four waveguide ports for three different crossed-arc structures. (b) Wide-field fluorescence image of a reference structure without a single-photon emitter. Upon pumping into the right port, we observe reduced background photoluminescence (PL) emerging from the orthogonal waveguide. (c) Structure with a single-photon emitter in the crossing. The blue dots are raw data of measurements, the red curve is a corresponding fit. Excitation is at 561 nm wavelength and 900 μW incident power. The inset illustrates that detection (red) is from the orthogonal waveguide with respect to the excitation (green). (d) The PL saturation curves compare the count rates of the structure with (blue) and a reference structure without (red) a single-photon emitter in the crossing. (e,f) As panels (c,d) but for detection from the excited waveguide, see inset in (e).