Optical Magnetometer Array Beam Splitter Light Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic field measurement systems, particularly for magnetoencephalography (MEG), face challenges with bulky and expensive superconducting quantum interference devices (SQUIDs) that are not suitable for mobile or wearable applications, and dense arrays of optically pumped magnetometers (OPMs) require efficient light distribution methods to achieve high spatial resolution and sensitivity.
Innovation Solution
An array of optically pumped magnetometers with an array of beam splitters arranged in columns and rows, configured to distribute light evenly to vapor cells, using polarizing beam splitters and waveplates to achieve uniform beam intensities and polarization control, allowing for efficient light delivery to multiple vapor cells without the need for individual lasers, thus enabling portable and wearable MEG systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SQUIDs are used for MEG measurement, then measurement sensitivity is improved, but device portability and ease of operation deteriorate due to cryogenic cooling requirements
Solution Approach 1:
The patent replaces expensive, complex SQUID systems with optically pumped magnetometers (OPMs) that use inexpensive vapor cells containing alkali metal vapors. These vapor cells can be operated at room temperature and do not require cryogenic cooling, making the system portable and easier to operate while maintaining high measurement sensitivity through optical pumping techniques
Solution Approach 2:
The patent changes the operating temperature parameter from cryogenic temperatures (required by SQUIDs) to room temperature (used by OPMs with vapor cells). This parameter change enables portability while maintaining measurement sensitivity through the use of optically pumped vapor cells that operate effectively at elevated temperatures
2Measurement precision
If an array of OPMs is used for high spatial resolution MEG, then measurement precision is improved, but device complexity increases due to need for multiple light sources
Solution Approach 1:
The patent merges multiple light sources into a single laser source that illuminates all vapor cells simultaneously. The vapor cells are arranged in an array and share common optical paths, allowing one laser to pump all cells at once. This merging dramatically reduces device complexity while maintaining the high spatial resolution achieved through the array configuration
Solution Approach 2:
The single laser source serves multiple functions by simultaneously pumping all vapor cells in the array. The optical system is designed so that one light source can deliver pump light to numerous vapor cells through shared optical paths, making the light source universal for the entire sensor array rather than requiring individual lasers for each cell
3Measurement precision
If vapor cells are placed close together for dense array, then spatial resolution is improved, but light distribution uniformity deteriorates
Solution Approach 1:
The patent introduces optical elements such as diffusers, lenses, and beam shaping components as intermediaries between the single laser source and the dense array of vapor cells. These intermediary optical components redistribute and equalize the light intensity across the array, ensuring uniform pump light delivery to all vapor cells even when they are closely spaced, thereby maintaining both high spatial resolution and light distribution uniformity
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 provides high spatial resolution and sensitivity in magnetic field measurement, is more compact and cost-effective, and reduces mechanical and thermal noise, making it suitable for unshielded environments and wearable devices.
Implementation Method 1
The array of beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells
Implementation Method 2
an array of optically pumped magnetometers (OPM)
Data Source
AI summary
An array of optically pumped magnetometers includes an array of vapor cells; and an array of beam splitters. The array of beam splitters is arranged into columns, including a first column, and rows. Each row and each column includes at least two of the beam splitters. The array of beam splitters is configured to receive light into the first column of the array and to distribute that light from the first column into each of the rows and to distribute the light from each of the rows into a plurality of individual light beams directed toward the vapor cells.