STTR Phase I: Feasibility Study of Chip-Scale Iodine Vapor Cell Fabrication

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) Phase I project is to improve measurement science. Currently, special low-pressure chambers known as "vapor cells" are made by hand in a select number of precision glassblowing shops and suffer from poor dimensional reproducibility, low production capacity, irregular sizes, and variable vapor composition leading to a multifaceted limitation in the marketplace. Optical frequency references on the market today are large, costly, and power-hungry, but are used in a variety of commercial opportunities throughout industrial metrology markets. This study aims to produce a repeatable recipe suitable for high-volume production of miniature vapor cells. The results of this study will lead to the scalable production of references that would be intrinsically trustworthy and perform well in a continuous manner over many years. This STTR Phase I project will leverage micromachining of glass and silicon to enable a new fabrication method for a traditionally handmade component: a glass-blown vapor cell. The research objective of this study is to test if such a method can yield a compact and reproducible vapor cell. Research will employ semiconductor processing techniques and optical frequency metrology to deduce the long-term stability and accuracy of these vapor cells in order to assess their suitability as optical frequency references. The anticipated technical results of this study include a potential pathway to a mass-produced optical frequency standard suitable for optical clocks, interferometers, and wavemeters. Such a technology would underpin accurate measurement science in high-performance optical measurement equipment. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.