Enabling atom-clad waveguide operation in a microfabricated alkali vapor-photonic integrated circuit

TL;DR

This paper presents a scalable, integrated alkali vapor-photonic device combining silicon nitride circuits with microfabricated vapor cells and rubidium dispensers, enabling controlled atom-photon interactions for quantum technologies.

Contribution

The work introduces a fully integrated, hermetically sealed vapor-PIC device with controlled Rb vapor release and suppression of photonic losses, advancing scalable quantum photonic integration.

Findings

Successful operation of integrated vapor-PIC device.

Controlled vapor density via pulsed dispenser activation.

Suppression of Rb-induced optical losses.

Abstract

Integrating alkali atomic vapors with nanophotonic devices offers a scalable route to quantum technologies that leverage strong atom-photon interactions. While there have been many approaches to such integration, the general reliance on traditional glass vapor cells, distilled alkali metals, and epoxy sealing limits reproducibility and scalability. Moreover, mitigating adverse Rb-photonics interactions is essential, particularly as devices become more compact and the alkali source lies in close proximity to the photonic elements. Here, we demonstrate the successful operation of compact and fully integrated devices that combine silicon nitride photonic integrated circuits (PICs) with microfabricated borosilicate vapor cells and pill-type rubidium (Rb) dispensers through hermetic seals via anodic bonding. We show how successful operation hinges on optically activating the dispenser in a low-power pulsed mode, releasing controlled amounts of Rb vapor on demand while mitigating photonic degradation. Simultaneously, a counter-propagating desorption laser completely suppresses Rb-induced losses and enables waveguide-based atomic vapor spectroscopy. Using this approach, we demonstrate repeatable control of vapor density by tuning activation pulse length, duty cycle, and device temperature. These results establish a compact, manufacturable, and scalable vapor-PIC device, and set the stage for future demonstrations in cavity quantum electrodynamics, quantum nonlinear optics, and chip-scale atomic sensors.