Wafer-level vapor cells filled with laser-actuated hermetic seals for integrated atomic devices
Abstract
Atomic devices such as atomic clocks and optically-pumped
magnetometers rely on the interrogation of atoms contained in a
cell whose inner content has to meet high standards of purity and
accuracy. Glass-blowing techniques and craftsmanship have evolved
over many decades to achieve such standards in macroscopic vapor
cells. With the emergence of chip-scale atomic devices, the need
for miniaturization and mass fabrication has led to the adoption of
microfabrication techniques to make millimeter-scale vapor cells.
However, many shortcomings remain and no process has been able to
match the quality and versatility of glass-blown cells. Here, we
introduce a novel approach to structure, fill and seal
microfabricated vapor cells inspired from the century-old approach
of glass-blowing, through opening and closing single-use zero-leak
microfabricated valves. These valves are actuated exclusively by
laser, and operate in the same way as the “make-seals” and
“break-seals” found in the filling apparatus of traditional cells.
Such structures are employed to fill cesium vapor cells at the
wafer-level. The make-seal structure consists of a glass membrane
that can be locally heated and deflected to seal a microchannel.
The break-seal is obtained by breaching a silicon wall between
cavities. This new approach allows adapting processes previously
restricted to glass-blown cells. It can also be extended to vacuum
microelectronics and vacuum-packaging of micro-electro-mechanical
systems (MEMS) devices.
Origin | Files produced by the author(s) |
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