Wafer-Scale Micro-Knife Sealed Vacuum Cells for Quantum Devices

TL;DR

This paper introduces wafer-scale micro-knife sealed vacuum cells for quantum devices, demonstrating robust, long-lasting, low-leakage atomic vapor cells with simplified fabrication for chip-scale quantum technologies.

Contribution

It presents a novel micro-knife bonding technique for wafer-scale vacuum cells, enabling robust, low-leak, long-lifetime atomic vapor cells suitable for quantum applications.

Findings

Vapor cells exhibit shear-force strength of ~15 MPa.

Long cell lifetimes exceeding 1 year.

Leak rates below 2.8 x 10^{-10} mBar·L/s.

Abstract

Advanced integration technologies greatly enhance the prospects and reliability of practical quantum sensors, atomic clocks, and quantum information technologies. The performance and proliferation of these devices at chip-scale is contingent upon developing low leak and low gas permeation vacuum cells using wafer-scale techniques. Here we demonstrate both evacuated atomic beam cells and atomic vapor cells using plastic deformation micro-knife bonding of selectively etched fused silica wafers. The cells are characterized using saturated absorption spectroscopy and fluorescence measurements. Vapor cells are mechanically robust exhibiting sheer-force strength ($\sim 15$MPa), demonstrate long lifetimes ($> 1$ year), low residual gas pressures $ (\ll 10^{-3} \, \text{mbar}) $, and leak rates below fine-leak testing sensitivity ($\ll 2.8 \times 10^{-10} \frac{\text{mBar} \cdot \text{L}}{\text{s}}$). Micro-knife bonding greatly simplifies the fabrication process for complex chip scale atom-beam devices and atomic vapor cells while identifying a path to future chip-scale cold atom devices, improved chip scale atomic clocks, and fieldable dissipation-dilution-limited optomechanics.