Frequency-Doubling Spectrometer Assembly for Infrared Speckle Imaging

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Solution Overview

Problem

Spectrometers for determining spectral information in the mid-infrared and far-infrared range are scarce and expensive due to the lack of suitable components for converting spectral information into spatial information without mechanical scanning.

Innovation Solution

A spectrometer assembly utilizing a radiation conversion element with a non-centrosymmetric material that frequency-doubles electromagnetic radiation, featuring a spatially inhomogeneous structure to generate spatial speckle images, combined with a detection unit and computing unit to retrieve spectral information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional spectrometers use gratings or prisms to convert spectral information into spatial information, then spectral measurement capability is achieved, but the components are scarce and expensive in mid-infrared and far-infrared regions

Engineering Contradiction:
Improvespectral measurement capabilityVSAvoidcomponent availability and cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical/optical components (gratings, prisms) with a radiation conversion element utilizing nonlinear optical effects. This substitution eliminates the need for expensive mid-infrared and far-infrared gratings and prisms, achieving spectral measurement capability through frequency doubling in a different wavelength range that can then be detected with available detectors.

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

Solution Approach 2:

The patent changes the operational parameters by using frequency doubling (second harmonic generation) to convert mid-infrared and far-infrared radiation into visible or near-infrared radiation. This parameter transformation allows the use of conventional, available detectors and optical components in the visible/near-infrared range, thereby resolving the scarcity and cost issues of mid-infrared/far-infrared components.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If fast spectrometers are designed without mechanical moving parts, then measurement speed is improved, but the ability to convert spectral information into spatial information becomes limited due to component scarcity

Engineering Contradiction:
Improvemeasurement speedVSAvoidavailability of conversion components
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces mechanical scanning systems with a stationary radiation conversion element that performs frequency doubling. This eliminates mechanical moving parts, achieving fast measurement speeds, while simultaneously resolving the component availability issue by using nonlinear optical materials that are more readily available than mid-infrared/far-infrared gratings or prisms.

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

Solution Approach 2:

The patent introduces a radiation conversion element as an intermediary that transforms the problematic mid-infrared/far-infrared radiation into a wavelength range where conventional components are available. This intermediary approach enables fast spectral measurement without mechanical parts while overcoming the component scarcity issue.

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

Enables fast and efficient determination of spectral information across a broad wavelength range without mechanical moving parts, utilizing non-centrosymmetric materials for frequency-doubling and spatial speckle imaging to enhance spectral resolution and reduce component costs.

Implementation Method 1

a radiation conversion element that comprises a non-centrosymmetric material to frequency-double at least a portion of the incoming electromagnetic radiation as the incoming electromagnetic radiation propagates through the radiation conversion element

Methodology Applied
Scientific EffectFrequency doubling: Second Harmonic Generation

Implementation Method 2

the frequency-doubled electromagnetic radiation comprises components propagating in a plurality of different directions; a detection unit arranged after the radiation conversion element with respect to a propagation direction defined by the incoming electromagnetic radiation, the detection unit being configured to record a spatial speckle image that is generated by spatial interference of the components of the frequency-doubled electromagnetic radiation with each other

Methodology Applied
Scientific EffectSpatial interference: Interference

Data Source

PatentEP4603806A1Spectrometer assembly
Publication Date: 2025.08.20 ETH ZURICH
  • EP4603806A1 patent drawingFigure 1~2
  • EP4603806A1 patent drawingFigure 3~5
  • EP4603806A1 patent drawingFigure 6

AI summary

A spectrometer assembly (1) for determining spectral information about incoming electromagnetic radiation (F) comprises a radiation conversion element (2) that comprises a non-centrosymmetric material to frequency-double at least a portion of the incoming electromagnetic radiation (F) as the incoming electromagnetic radiation (F) propagates through the radiation conversion element (2). The radiation conversion element (2) exhibits a spatially inhomogeneous structure such that the frequency-doubled electromagnetic radiation (SH) comprises components propagating in a plurality of different directions. The spectrometer assembly further comprises a detection unit (3) which is configured to record a spatial speckle image that is generated by spatial interference of the components of the frequency-doubled electromagnetic radiation (SH) with each other, and a computing unit (4) which is configured to retrieve spectral information about the electromagnetic radiation (F) based on said spatial speckle image.