  Despite the realizations of spin-orbit (SO) coupling and synthetic gauge
fields in optical lattices, the associated time-reversal symmetry breaking, and
1D nature of the observed SO coupling pose challenges to obtain intrinsic $Z_2$
topological insulator. We propose here a model optical device for engineering
intrinsic $Z_2$ topological insulator which can be easily set up with the
existing tools. The device is made of a periodic lattice of quantum
mechanically connected atomic wires (dubbed SO wires) in which the laser
generated SO coupling ($\alpha_{\bf k}$, with ${\bf k}$ being the momentum) is
reversed in every alternating wires as $\pm\alpha_{\bf k}$. The associated
small Zeeman terms are also automatically reversed in any two adjacent SO
wires, which allow to effectively restore the global time-reversal (TR)
symmetry. Therefore, the two SO wires serve as the TR partner to each other
which is an important ingredient for $Z_2$ topological insulators according to
the Kane-Mele model. These properties ensure a non-trivial $Z_2$ invariant
topological insulator phase with protected edge states. We also discuss that a
non-local current measurement can be used to detect the chiral edge states.
