Micro-Electro-Mechanical System Vapor Cells with Passivated Internal Cavities

Micro-Electro-Mechanical vapor cells are key components in atom-based quantum sensors, such as clocks, gyroscopes, electric field sensors and magnetometers. MEMs vapor cell fabrication for Rydberg atom radio frequency sensors is particularly demanding. The Rydberg states used for the sensor can shift in a constant electric field which can be generated by the internal surfaces of the vapor cell cavity. MEMs vapor cells with low background electric fields are superior devices for Rydberg atom sensors. Known inert, organic coatings cannot survive the bonding temperatures required for conventional anodic bonding of a MEMs vapor cell. Applying inert, organic coatings to the internal cavities of MEMs vapor cells is a longstanding challenge. In this presentation, we present a low temperature bonding scheme that is compatible with coating the internal cavity of a MEMs vapor cell with Octadecyltrichlorosilane [1]. The coating prevents the Cs used in the vapor cell from sticking to the walls. Spectral linewidths of 300 kHz are obtained using Rydberg spectroscopy, with energy shifts corresponding to electric fields ~ 10 mV/cm.

[1] R. Pandiyan et al., arXiv:2512.00245 (2025).