  Self-assembled, epitaxially-grown InAs/GaAs quantum dots are promising
semiconductor quantum emitters that can be integrated on a chip for a variety
of photonic quantum information science applications. However, self-assembled
growth results in an essentially random in-plane spatial distribution of
quantum dots, presenting a challenge in creating devices that exploit the
strong interaction of single quantum dots with highly confined optical modes.
Here, we present a photoluminescence imaging approach for locating single
quantum dots with respect to alignment features with an average position
uncertainty < 30 nm (< 10 nm when using a solid immersion lens), which
represents an enabling technology for the creation of optimized single quantum
dot devices. To that end, we create quantum dot single-photon sources, based on
a circular Bragg grating geometry, that simultaneously exhibit high collection
efficiency (48 % +/- 5 % into a 0.4 numerical aperture lens, close to the
theoretically predicted value of 50 %), low multiphoton probability (g(2)(0) <1
%), and a significant Purcell enhancement factor (~ 3).
