  Among the diverse platforms of quantum light sources, epitaxially grown
semiconductor quantum dots (QDs) are one of the most attractive workhorses for
realizing various quantum photonic technologies owing to their outstanding
brightness and scalability. There exist various material systems for these QDs
based on their appropriate emission bandwidth; however, only a few material
systems have successfully grown single or low-density QDs, which are essential
for quantum light sources. In most other material systems, it is difficult to
realize low-density QDs, and the mesa-etching process is usually undergone in
order to reduce their density. Nevertheless, the etching process irreversibly
destroys the medium near the QD, which is detrimental to in-plane device
integration. In this study, we apply a nondestructive luminescence picking
method termed as nanoscale focus pinspot (NFP) using helium ion microscopy to
reduce the luminous QD density while retaining the surrounding medium. Given
that the NFP can precisely manipulate the luminescence at nanoscale resolution,
a photonic device can be deterministically fabricated on the target QD matched
from both spatial and spectral points of view. After applying the NFP, we
extract only a single QD emission out of the high-density ensemble QD emission.
Moreover, the photonic structure of a circular Bragg reflector is
deterministically integrated with the selected QD, and the extraction
efficiency of the QD emission has been improved 27 times. Furthermore, this
technique does not destroy the medium and only controls the luminescence.
Hence, it is highly applicable to various photonic structures, including
photonic waveguides or photonic crystal cavities regardless of their materials.
