Chip-Scale Atomic Clock Physics Module Optical Patterns

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Solution Overview

Problem

The existing physics modules of chip-scale atomic clocks are hindered by increased volume and power consumption due to the inclusion of quarter wave plates and polarization beam splitters, which are not suitable for miniaturized designs.

Innovation Solution

The implementation of optical patterns with a thickness less than typical quarter wave plates and polarization beam splitters, made of materials like silicon, silicon nitride, or titanium oxide, that circularly polarize the laser beam and reduce the volume and power consumption of the physics module by providing efficient phase retardation and beam splitting without the need for additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quarter wave plate and polarization beam splitter are used to circularly polarize and split the laser beam, then the beam polarization and splitting functions are achieved, but the volume and power consumption of the physics module increase

Engineering Contradiction:
Improvebeam polarization and splitting functionVSAvoidphysics module volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent combines the quarter wave plate and polarization beam splitter functions into a single integrated optical component. This component simultaneously performs circular polarization and beam splitting operations that were previously separated, thereby reducing the overall volume and component count while maintaining the required optical functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated optical component is designed to perform multiple functions: it acts as both a quarter wave plate for circular polarization and a polarization beam splitter for separating orthogonal polarization components. This multi-functional design eliminates the need for separate components, directly addressing the volume reduction goal.

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

2Reliability

If quarter wave plate and polarization beam splitter are used to circularly polarize and split the laser beam, then the beam polarization and splitting functions are achieved, but the power consumption of the physics module increases

Engineering Contradiction:
Improvebeam polarization and splitting functionVSAvoidphysics module power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

By merging the quarter wave plate and polarization beam splitter into one integrated component, the patent reduces the total power consumption associated with maintaining and operating multiple separate optical elements. The integrated design optimizes light transmission efficiency and reduces parasitic losses.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The universal optical component performs both polarization and beam splitting functions in a single pass through the component, eliminating the need for additional optical elements that would consume power. This multi-functional approach directly reduces the overall power budget of the physics module.

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

3Reliability

If traditional quarter wave plate and polarization beam splitter are used, then adequate phase retardation and beam splitting are achieved, but the component thickness and volume are excessive for chip-scale integration

Engineering Contradiction:
Improvephase retardation and beam splitting performanceVSAvoidoptical component thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent transitions from bulk optical components to thin-film optical structures. By depositing multiple layers of materials with different refractive indices on a substrate, the quarter wave plate and beam splitter functions are achieved in a planar, two-dimensional configuration rather than requiring thick three-dimensional components, enabling chip-scale integration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the physical parameters of the optical component by using thin-film deposition techniques to create layers with precisely controlled thicknesses and refractive indices. This allows the optical functionality to be achieved with much reduced physical dimensions compared to traditional bulk optics.

Inventive Principle:
Principle #35Parameter changes

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 approach reduces the volume and power consumption of the chip-scale atomic clock while maintaining the stability and performance enhancements achieved through coherent population trapping spectroscopy, by efficiently polarizing the laser beam and splitting it based on polarization directions.

Implementation Method 1

optical patterns with a thickness less than typical quarter wave plates and polarization beam splitters, made of materials like silicon, silicon nitride, or titanium oxide, that circularly polarize the laser beam and reduce the volume and power consumption of the physics module by providing efficient phase retardation

Methodology Applied
Scientific EffectPhase retardation:

Implementation Method 2

efficiently polarizing the laser beam and splitting it based on polarization directions

Methodology Applied
Scientific EffectPolarization beam splitting:

Implementation Method 3

The alkali vapor may absorb a portion of a laser beam having a resonant frequency

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Implementation Method 4

The detector may determine whether a frequency difference between side bands of the transmitted beam is matched with a natural frequency of an atom by using spectroscopy of coherent population trapping (CPT)

Methodology Applied
Scientific EffectCoherent population trapping spectroscopy:

Data Source

PatentEP3564759B1Physics module of chip-scale atomic clock
Publication Date: 2022.12.07 KOREA RES INST OF STANDARDS & SCI
  • EP3564759B1 patent drawingFigure 1
  • EP3564759B1 patent drawingFigure 2~3
  • EP3564759B1 patent drawingFigure 4

AI summary

An embodiment of the inventive concept provides a physics module of a chip-scale atomic clock. The physics module includes: a housing; a laser source disposed in the housing and generating a laser beam; a vapor cell disposed above the laser source to generate a transmitted beam from the laser beam; and a detector disposed above the vapor cell to detect the transmitted beam. Here, the vapor cell may include a plurality of optical patterns configured to polarize the laser beam.