  Atom-light interactions in nano-scale systems hold great promise for novel
technologies based on integrated emitters and optical modes. We present the
design architecture, construction method, and characterization of an all-glass
alkali-metal vapor cell with nanometer-scale internal structure. Our cell has a
glue-free design which allows versatile optical access, in particular with high
numerical aperture optics, and incorporates a compact integrated heating system
in the form of an external deposited ITO layer. By performing spectroscopy in
different illumination and detection schemes, we investigate atomic densities
and velocity distributions in various nanoscopic landscapes. We apply a
two-photon excitation scheme to atoms confined in one dimension within our
cells, achieving resonance line-widths more than an order of magnitude smaller
than the Doppler width. We also demonstrate sub-Doppler line-widths for atoms
confined in two dimensions to micron-sized channels. Furthermore, we illustrate
control over vapor density within our cells through nano-scale confinement
alone, which could offer a scalable route towards room-temperature devices with
single atoms within an interaction volume. Our design offers a robust platform
for miniaturized devices that could easily be combined with integrated photonic
circuits.
