Diamond Sensor Unit With Optical Isolation for High-Voltage Magnetic Sensing

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Solution Overview

Problem

Existing sensors using NV centers in diamonds face damage and signal intensity limitations in high-voltage environments due to electrical discharge and electromagnetic interference, limiting their ability to accurately measure magnetic fields remotely.

Innovation Solution

A diamond sensor unit design that includes a diamond with a color center, excitation light and electromagnetic wave irradiation, a patch antenna for receiving electromagnetic waves, and an optical waveguide for transmitting light, allowing remote magnetic field detection without damage in high-voltage environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional sensor configuration is used in high-voltage environments, then the sensor can detect magnetic fields, but the sensor components are damaged by electrical discharge and electromagnetic interference

Engineering Contradiction:
Improvesensor durabilityVSAvoidelectrical discharge damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The sensor system is divided into two spatially separated parts: the diamond sensor element positioned in the high-voltage environment for magnetic field detection, and the readout components (photodetector, electronics) positioned in a low-voltage safe zone. This segmentation allows the sensitive detection function to remain in the hazardous environment while protecting the vulnerable readout electronics from electrical discharge and electromagnetic interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An optical fiber acts as an intermediary medium to transmit signals between the diamond sensor element in the high-voltage environment and the readout components in the safe zone. The optical fiber serves as an electrical insulator that carries information without conducting electricity, thereby protecting the system from electrical discharge while enabling communication between separated components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the sensor is positioned close to the high-voltage source for accurate measurement, then measurement precision improves, but the risk of electrical discharge and electromagnetic interference increases

Engineering Contradiction:
Improvemagnetic field detection accuracyVSAvoidelectromagnetic interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system segments the sensor functionality so that the diamond element can be positioned close to the high-voltage source for accurate magnetic field measurement, while the readout electronics are separated in a protected environment. This spatial segmentation enables close proximity measurement without exposing sensitive electronics to electromagnetic interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system replaces electrical signal transmission with optical signal transmission using a optical fiber. This substitution eliminates the problem of electromagnetic interference affecting signal transmission, as optical signals are immune to electromagnetic fields. The diamond sensor element can thus be positioned close to the high-voltage source without compromising signal integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If simple lens configuration is used, then device complexity is reduced, but optical performance and signal collection efficiency deteriorate

Engineering Contradiction:
Improveoptical system complexityVSAvoidsignal collection efficiency
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The optical fiber serves as an intermediary that simplifies the overall optical system by directly coupling the diamond sensor element to the readout photodetector. This eliminates the need for complex lens assemblies while maintaining efficient light transmission through the optical fiber's total internal reflection mechanism, thereby reducing device complexity without sacrificing signal collection efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The design enables accurate measurement of magnetic fields and other physical quantities in high-voltage environments by using a patch antenna for improved directionality and an optical waveguide to separate and transmit light, reducing component damage and enhancing detection accuracy.

Implementation Method 1

an LED 900 disposed on a substrate 912 emits green light for exciting the NV center of a diamond 904. The emitted light passes through an SPF (Short Pass Filter) 902, and subsequently enters diamond 904 disposed on a substrate 914. Accordingly, electrons at the NV center are brought into an excited state. When the excited electrons return to the original ground state, red fluorescent light is emitted from diamond 904.

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a first patch antenna configured to receive electromagnetic waves; an electromagnetic wave irradiation part provided separately from the first patch antenna and configured to irradiate the diamond with the electromagnetic waves received by the first patch antenna via a transmission path

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

an optical waveguide configured to transmit the excitation light and the radiated light

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4286877B1Diamond sensor unit
Publication Date: 2025.09.24 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP4286877B1 patent drawingFigure 1
  • EP4286877B1 patent drawingFigure 2
  • EP4286877B1 patent drawingFigure 3~4

AI summary

A diamond sensor unit includes: a diamond having a color center with electron spin; an excitation light irradiation part that irradiates the diamond with excitation light; a first patch antenna that receives electromagnetic waves; an electromagnetic wave irradiation part that irradiates the diamond with the electromagnetic waves received by the first patch antenna; a detection part that detects radiated light radiated from the color center of the diamond after the diamond is irradiated with the excitation light and the electromagnetic waves; and an optical waveguide that transmits the excitation light and the radiated light.