  An on-chip multi-grating device is proposed to interface single-atoms and
integrated photonic circuits, by guiding and focusing lasers to the area with
~10um above the chip for trapping, state manipulation, and readout of single
Rubidium atoms. For the optical dipole trap, two 850 nm laser beams are
diffracted and overlapped to form a lattice of single-atom dipole trap, with
the diameter of optical dipole trap around 2.7um. Similar gratings are designed
for guiding 780 nm probe laser to excite and also collect the fluorescence of
87Rb atoms. Such a device provides a compact solution for future applications
of single atoms, including the single photon source, single-atom quantum
register, and sensor.
