Demonstration of atom interrogation using photonic integrated circuits anodically bonded to ultra-high vacuum envelopes for epoxy-free scalable quantum sensors
Sterling E. McBride, Cale M. Gentry, Christopher E. Holland, Colby L. Bellew, Kaitlin Moore, Alan M. Braun
Reliable integration of photonic integrated circuits (PICs) into quantum sensors has the potential to drastically reduce sensor size, ease manufacturing scalability, and improve performance in applications where the sensor is subject to high accelerations, vibrations, and temperature changes. In a traditional quantum sensor assembly, free-space optics are subject to pointing inaccuracies and temperature-dependent misalignment. Moreover, the use of epoxy or sealants for affixing either free-space optics or PICs within a sensor vacuum envelope leads to sensor vacuum degradation and is difficult to scale. In this paper, we describe the hermetic integration of a PIC with a vacuum envelope via anodic bonding. We demonstrate utility of this assembly with two proof-of-concept atom-interrogation experiments: (i) spectroscopy of a cold-atom sample using a grating-emitted probe; (ii) spectroscopy of alkali atoms using an evanescent field from an exposed ridge waveguide. This work shows a key process step on a path to quantum sensor manufacturing scalability.
Reliable integration of photonic integrated circuits (PICs) into quantum sensors has the potential to drastically reduce sensor size, ease manufacturing scalability, and improve performance in applications where the sensor is subject to high accelerations, vibrations, and temperature changes. In a traditional quantum sensor assembly, free-space optics are subject to pointing inaccuracies and temperature-dependent misalignment. Moreover, the use of epoxy or sealants for affixing either free-space optics or PICs within a sensor vacuum envelope leads to sensor vacuum degradation and is difficult to scale. In this paper, we describe the hermetic integration of a PIC with a vacuum envelope via anodic bonding. We demonstrate utility of this assembly with two proof-of-concept atom-interrogation experiments: (i) spectroscopy of a cold-atom sample using a grating-emitted probe; (ii) spectroscopy of alkali atoms using an evanescent field from an exposed ridge waveguide. This work shows a key process step on a path to quantum sensor manufacturing scalability.
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.
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.
Photonic integrated circuits (PICs) offer compact and scalable solutions for trapped-ion quantum technologies. This work demonstrates photonic platforms that promise the potential integration of photonic components for light delivery and control across ultraviolet (UV) to near-infrared (NIR) wavelengths. Passive waveguides and beam-shaping structures provide precise and stable optical addressing of ions, while active elements such as modulators and switches enable dynamic, on-chip control for quantum operations. Materials like aluminum oxide (Al2O3) and aluminum nitride (AlN) are evaluated to illustrate how functionality can be tailored to spectral needs. These integrated photonic systems reduce reliance on bulky free-space optics, improve alignment stability, and support future development of compact quantum sensors, atomic clocks, and scalable quantum processors.
Integrated photonic circuits based on suspended photonic rib waveguides, which can be used for coherent trapping, guiding, and splitting of ultra-cold neutral atoms in two-color evanescent light fields near their surfaces, are described. Configurations of quantum inertial sensors based on such integrated atomo-photonic waveguides, which are simultaneously guiding photons and atoms along the same paths, are presented. The difference between free-space and guided atom interferometers in the presence of external forces is explained. The theoretical and technological challenges, to be overcome on the way to the realization of such a platform for quantum technologies, are discussed.
We report the current progress in the development of a compact, deployable cold-atom interferometry sensor platform towards atomic sensors for position, navigation, and time (PNT) applications.A simplified atomic sensor head with diffractive optics, a fixed-alignment optical package, and photonic-integrated-circuit (PIC) compatible laser architecture [1] are essential for its compactness and deployability.This cold atom sensor platform can be generally applied to gravimeters, accelerometers, gyroscopes, and clocks, and the sensor platform includes significant engineering efforts in the development of grating-mirror magneto-optical traps (G-MOTs), ridgid structural design, a custom titanium vacuum package with passive pumping, and silicon photonics multi-channel on-chip single sideband modulators.
Quantum sensors have the potential to transform numerous applications across a broad range of fields from precision timing to electro-magnetic field sensing, medical imaging, gravimetry, to inertial sensing. Despite promising performances in laboratory experiments, quantum sensors have yet to be widely deployed in real-world applications at large scale. The large-scale adoption of quantum sensors has been hampered by the high SWaP-c and their sensitivity to environmental factors. Photonic integrated circuits have emerged as an enabling technology for quantum sensors to reduce SWaP-c, enhance fieldability, and add enhanced functionality. Honeywell has developed state-of-the-art capabilities in Silicon Nitride (SiN) and other photonics platforms, to enable low-swap quantum sensors ranging from atomic clocks, Rydberg electromagnetic field sensors, and NV diamond magnetometers among others. In this talk we will give an overview of how Honeywell is using photonic integrated circuits to enable a variety of quantum sensing and timing technologies for aerospace applications. Low-loss SiN waveguides can be used to deliver light to the quantum system in a compact form factor, produce high Q-optical cavities for narrow-linewidth lasers, tunably filter frequency components, or to generate optical combs. Mode-matched edge couplers can efficiently transfer light from fiberto- chip or chip-to-chip. Other photonic platforms such as diamond or thin-film lithium niobate (TFLN) can be integrated with a SiN platform in either hybrid or heterogenous configurations to enable quantum magnetometry and laser frequency tuning or modulation in ultra-compact form factors. We will discuss the advantages and remaining challenges for using photonic integrated circuits to advance quantum sensors to the point where they can be adopted in mainstream applications.