Optical Fiber Coupler for Precise Wavelength Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems face challenges in accurately deriving wavelength information, especially for light with complex spectra that do not have a plurality of peaks.

Innovation Solution

An optical element comprising a first optical fiber and a second optical fiber coupled in a coupling region, where the center wavelength of the first optical fiber is set to a transmittance range of 10% to 90%, allowing light to be transmitted and reflected based on wavelength, enabling accurate separation and detection of light on both fibers for precise wavelength information derivation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a spectrometer is used to derive wavelength information, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvewavelength information accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential wavelength discrimination function from a complete spectrometer system. Instead of using a full spectrometer with dispersive elements and array detectors, it isolates the core wavelength separation capability and implements it through a simplified interferometric arrangement with single-point detection, thereby reducing device complexity while maintaining measurement precision

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified optical path that copies the essential wavelength separation principle of spectrometers but implements it through a different, more compact configuration. The interferometric setup replicates the spectral analysis function using a fundamentally different optical architecture that is less complex and more cost-effective

Inventive Principle:
Principle #26Copying

2Device complexity

If traditional filtering methods are used for wavelength detection, then device complexity is reduced, but measurement precision deteriorates for complex spectra

Engineering Contradiction:
Improvesystem simplicityVSAvoidwavelength information accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces traditional mechanical filtering methods (such as etalon filters or diffraction gratings) with an interferometric measurement approach. This substitution uses interference patterns to encode wavelength information, enabling precise wavelength derivation through computational analysis of interference signals rather than physical spectral separation, thus maintaining simplicity while improving precision for complex spectra

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

Solution Approach 2:

The patent changes the measurement parameter from direct spectral intensity distribution (as in spectrometers) to interferometric signal characteristics. By measuring interference patterns and deriving wavelength information from phase and amplitude relationships in the interferogram, the system achieves high precision wavelength detection for complex spectra using a simpler optical configuration

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

Enables accurate derivation of wavelength information regardless of the spectrum shape, including lights with multiple peaks, without the need for a spectrometer, at a lower cost and with improved accuracy.

Implementation Method 1

the light is transmitted and reflected according to a wavelength of the light allowed to propagate through the first optical fiber in the coupling region

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 2

a second optical fiber having a coupling region coupled to the first optical fiber

Methodology Applied
Scientific EffectOptical coupling:

Data Source

PatentEP4692875A1Optical element, wavelength detection unit, and light generation unit
Publication Date: 2026.02.11 HAMAMATSU PHOTONICS KK
  • EP4692875A1 patent drawingFigure 1
  • EP4692875A1 patent drawingFigure 2
  • EP4692875A1 patent drawingFigure 3

AI summary

An optical fiber coupler 5 is an optical element for separating light whose wavelength is to be measured, and includes a first optical fiber 20 allowing light having a predetermined center wavelength to propagate, and a second optical fiber 30 having a coupling region 50 coupled to the first optical fiber 20, in which the center wavelength of the light allowed to propagate through the first optical fiber 20 is a wavelength at which a transmittance in the coupling region 50 is within a range of 10% to 90%, and the light is transmitted and reflected according to a wavelength in the coupling region 50.