Integrated Vacuum Cell PIC Sealing for Precise Atomic Sensing

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Solution Overview

Problem

Existing atomic sensors face challenges in maintaining high vacuum conditions while integrating various measurement components due to contamination and interference from external elements, limiting their accuracy and precision.

Innovation Solution

The integration of a vacuum envelope with a photonic integrated circuit (PIC) using anodic bonding, where the PIC forms a wall of the vacuum envelope and includes nonplanar waveguides with bridge structures for hermetic sealing, allowing for optical access and reduced contamination, thus maintaining high vacuum conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a vacuum envelope is used to maintain high vacuum conditions, then measurement accuracy is improved, but device complexity increases due to integration of multiple components

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the vacuum envelope with the photonic integrated circuit substrate, where the substrate itself forms a wall of the vacuum envelope. This integration eliminates the need for separate vacuum chamber structures and reduces the number of discrete components, thereby maintaining measurement accuracy while reducing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The photonic integrated circuit substrate serves dual functions: as the platform for photonic components and as a structural wall of the vacuum envelope. This multi-functionality reduces the overall component count and simplifies the device structure while maintaining the high vacuum environment necessary for accurate measurements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If various measurement components are placed outside the vacuum volume, then device complexity is reduced, but measurement accuracy deteriorates due to contamination and interference

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent integrates measurement components directly onto the vacuum envelope substrate, allowing them to be positioned within or adjacent to the vacuum volume. This integration enables components to interact with the vacuum environment without requiring separate external mounting structures, thereby maintaining measurement accuracy while avoiding excessive complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The vacuum envelope substrate acts as an intermediary that allows measurement components to access the vacuum environment while maintaining the vacuum seal. This intermediary structure enables precise measurements by allowing controlled interaction between components and the vacuum volume without direct contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Illumination intensity

If nonplanar waveguides are used to transmit light into vacuum cavities, then optical access is improved, but manufacturing difficulty increases due to hermetic sealing requirements

Engineering Contradiction:
Improveoptical accessVSAvoidmanufacturing difficulty
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent implements planar bridge structures at specific locations where waveguides interface with the vacuum envelope. These localized planar regions provide hermetic sealing surfaces exactly where needed, while the rest of the waveguide structure can maintain its nonplanar configuration for optimal optical access. This selective application of planarity resolves the manufacturing difficulty without compromising optical performance.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration results in robust, compact, and easily manufacturable vacuum cell assemblies that provide ultra-high vacuum environments for precise atomic measurements with reduced interference, enhancing the accuracy and sensitivity of atomic sensors.

Implementation Method 1

The photonic integrated circuit includes one or more waveguides configured in a substrate. Each waveguide is configured to transmit light from a light input surface to an interior of the vacuum envelope.

Methodology Applied
Scientific EffectLight transmission through waveguides: Waveguide (optics)

Implementation Method 2

Each waveguide includes a bridge structure coupled to the one or more walls of the vacuum envelope and planar with the portion of the top surface of the substrate. The bridge structure is configured to guide light through the bridge structure.

Methodology Applied
Scientific EffectLight guidance through bridge structure: Waveguide (optics)

Implementation Method 3

The vacuum envelope includes one or more walls coupled to a top surface of the substrate through anodic bonding

Methodology Applied
Scientific EffectAnodic bonding: Anodising

Data Source

PatentEP4091005B1Integrated vacuum cell assemblies
Publication Date: 2026.01.28 SRI INTERNATIONAL
  • EP4091005B1 patent drawingFigure 1A~1B
  • EP4091005B1 patent drawingFigure 2A~2C
  • EP4091005B1 patent drawingFigure 3A~3C

AI summary

The disclosure describes vacuum cell assemblies that integrate a vacuum envelope with a photonic integrated circuit (PIC). Walls of the vacuum envelope are coupled to the PIC, such as through anodic bonding, so that the PIC forms at least one wall of the vacuum envelope and provides an optically accessible medium and surface for transmitting and distributing light into various cavities of the vacuum envelope through one or more nonplanar waveguides. A surface of the PIC may include a material that is compatible with a material of the walls of the vacuum envelope, such as a silicon-based vacuum envelope bonded to a silicon nitride or amorphous silicon surface of the PIC. Each waveguide may include a bridge structure that forms a planar surface for tightly bonding with the vacuum envelope and preserves properties of the transmitted light between opposing sections of the waveguide.