Design Considerations for Micro-Glassblown Atomic Vapor Cells

Abstract

This paper presents a design process for miniaturized atomic vapor cells using the micro-glassblowing process. It discusses multiple design considerations, including cell geometry, optical properties, materials, and surface coating. The geometry and the optical properties were studied using experimentally verified analytical and Finite Element Models (FEM). The cell construction material and surface coating were the focus of our experimental study on factors that affect the relaxation time (T2) of nuclear spins. We showed that the wafer-level coating process with Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> increased the 131Xe T2 by 3× and by switching from Borosilicate glass (Pyrex) to Aluminosilicate glass (ASG), T2 was improved by 2.5×, for the same species. The improvement in the T2 is projected to reduce the ARW of an NMR gyro and the sensitivity of an NMR magnetometer by 3× with Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> coated cells and by 2.5× with ASG cells.