Quantum Interferometer Spectroscopy for Time-Resolved High Resolution

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Solution Overview

Problem

Existing quantum absorption spectroscopy methods face challenges in achieving high spectral resolution and broad spectral bandwidth, particularly when using pulsed light sources for generating entangled photon pairs, leading to degraded spectral resolution and difficulty in time-resolved measurements.

Innovation Solution

A quantum absorption spectroscopy method and system that employs a pulsed light source to generate entangled photon pairs, utilizing a quantum interferometer and photodetector to calculate absorption spectroscopy characteristics through quantum interference signals, and Fourier transforms of these signals to improve spectral resolution and enable time-resolved measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If pulsed light source is used to generate entangled photon pairs, then time-resolved measurement capability is improved, but spectral resolution is degraded

Engineering Contradiction:
Improvetime-resolved measurement capabilityVSAvoidspectral resolution
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The patent divides the measurement process into two distinct paths: the signal photon path for high-resolution spectroscopy and the idler photon path for time-resolved measurements. By segmenting the entangled photon pairs into separate functional paths, the system achieves both high spectral resolution (through signal photons) and time-resolved capability (through idler photons) simultaneously, resolving the contradiction between these two requirements.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If broadband light source is used to generate entangled photon pairs, then spectral bandwidth is improved, but spectral resolution is degraded

Engineering Contradiction:
Improvespectral bandwidthVSAvoidspectral resolution
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the spectral information between entangled photon pairs, where the signal photons maintain high spectral resolution for precise measurements, while the idler photons provide broad spectral bandwidth for versatile applications. This segmentation allows the system to simultaneously achieve both high spectral resolution and broad bandwidth without the trade-off that would occur with conventional single-source approaches.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If conventional light source is used for generating entangled photon pairs, then system simplicity is maintained, but both spectral resolution and time-resolved measurement performance are degraded

Engineering Contradiction:
Improvesystem simplicityVSAvoidspectral resolution and time-resolved measurement performance
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent employs a simple pump light source that generates entangled photon pairs, then segments these pairs into signal and idler photons with distinct functions. This approach maintains system simplicity at the light source level while achieving high spectral resolution and time-resolved measurement performance through the segmented photon paths, avoiding the need for complex multiple light sources or sophisticated optical systems.

Inventive Principle:
Principle #1Segmentation

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 method and system enhance the performance of quantum absorption spectroscopy by maintaining spectral resolution and enabling time-resolved analysis, overcoming the conventional degradation issues associated with pulsed light sources.

Implementation Method 1

a quantum interferometer configured to cause quantum interference between a plurality of physical processes in each of which an entangled photon pair of a signal photon and an idler photon is generated from the pump light

Methodology Applied
Scientific EffectSpontaneous parametric down-conversion:

Implementation Method 2

a photodetector that detects the signal photon

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

calculating an absorption spectroscopy characteristic of the sample based on at least one Fourier spectrum obtained by Fourier transform of the at least one quantum interference signal

Methodology Applied
Scientific EffectFourier transform:

Data Source

PatentEP4700346A1Quantum absorption spectroscopy method and quantum absorption spectroscopy system
Publication Date: 2026.02.25 KYOTO UNIV
  • EP4700346A1 patent drawingFigure 1
  • EP4700346A1 patent drawingFigure 2
  • EP4700346A1 patent drawingFigure 3

AI summary

A quantum absorption spectroscopy method includes first to third steps. The first step is outputting pump light to a quantum interferometer (2), the pump light being at least one of pulsed light and broadband light. The quantum interferometer (2) is configured to cause quantum interference between a plurality of physical processes in each of which an entangled photon pair of a signal photon and an idler photon is generated from the pump light, and a sample is disposed on a propagation path of the idler photon. The second step is acquiring at least one quantum interference signal from the quantum interferometer (2). Each of the at least one quantum interference signal is a signal corresponding to the number of the signal photon detected by a photodetector (3) when a phase of one of the signal photon and the idler photon is changed. The third step is calculating an absorption spectroscopy characteristic of the sample based on at least one Fourier spectrum obtained by Fourier transform of the at least one quantum interference signal.