Locally-sealed microfabricated vapor cells filled from an ex situ Cs source

TL;DR

This paper introduces a new method for filling and sealing microfabricated cesium vapor cells using local microchannel sealing, enabling more versatile fabrication and improved cell performance for miniature atomic devices.

Contribution

A novel local sealing technique for microfabricated cesium vapor cells that allows for diverse coatings and lower background pressure, surpassing traditional wafer-level bonding methods.

Findings

Enables deposition of temperature-sensitive coatings

Achieves lower background gas pressure

Supports filling with various atomic or molecular species

Abstract

Microfabricated alkali vapor cells are key to enable miniature devices such as atomic clocks and optically pumped magnetometers with reduced size, weight and power. Yet, more versatile fabrication methods are still needed to further expand their use cases. Here, we demonstrate a novel approach to collectively fill and seal microfabricated cesium cells using locally-sealed microchannels patterned within one of the glass substrates comprising the cells. Unlike current methods that rely on wafer-level anodic bonding as the last sealing step, an approach based on local sealing opens the path to features so far limited to traditional glass-blown cells, including the ability to deposit temperature-sensitive antirelaxation coatings, reaching lower background gas pressure without an additional gettering material or filling with diverse atomic or molecular species.