Gradient-Index Grating Deposition for Broad Wavelength Efficiency

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Solution Overview

Problem

Conventional diffraction gratings are wavelength-sensitive, limiting their efficiency to a specific range of wavelengths, and the diffraction efficiency of single-material gratings cannot meet growing consumer demands.

Innovation Solution

The method involves forming grating structures with a varying refractive index by controlling the deposition of materials in a process chamber, using multiple targets and varying voltage and gas flow rates to create a refractive index gradient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional diffraction grating with uniform material is used, then the manufacturing process is simple, but the diffraction efficiency is limited and wavelength range is narrow

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddiffraction efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by varying the refractive index of the grating material during deposition. By controlling deposition parameters (power, gas flow rates) to create a refractive index gradient within the grating structures, the diffraction efficiency is enhanced and operational wavelength range is expanded while maintaining a single deposition process

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates composite material structures by forming grating structures with varying refractive index profiles within a single material layer. The refractive index varies from approximately 1.4 to 2.0 within the grating material, effectively creating a composite optical structure that improves performance without requiring multiple material layers

Inventive Principle:
Principle #40Composite materials

2Device complexity

If a conventional diffraction grating is used, then the device structure is simple, but the operational wavelength range is limited

Engineering Contradiction:
Improvegrating structure complexityVSAvoidoperational wavelength range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent changes the refractive index parameter within the grating material during deposition to create a gradient profile. This allows a single grating structure to operate efficiently across a broader wavelength range (e.g., 400-700nm) without increasing structural complexity or requiring multiple grating layers

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If multiple material layers are deposited to achieve varying refractive index, then the refractive index distribution can be controlled, but the manufacturing process becomes complex

Engineering Contradiction:
Improverefractive index distribution controlVSAvoiddeposition process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by establishing a refractive index gradient during the initial deposition process itself, rather than requiring subsequent processing steps. By controlling deposition parameters in real-time, the desired refractive index profile is achieved in a single continuous deposition, avoiding the need for multiple material layers or post-deposition treatments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses parameter changes during deposition (power, gas flow rates) to control the refractive index distribution directly during the deposition process, achieving precise refractive index control without increasing process complexity through multiple deposition steps

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

This approach enhances diffraction efficiency and expands the operational wavelength range, making the grating device less sensitive to waveband selection and improving performance across a broader spectrum.

Implementation Method 1

depositing a grating material on the substrate to form a grating material layer on the substrate

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Data Source

PatentEP4345517B1Method forming grating device
Publication Date: 2025.11.05 VISERA TECH CO LTD
  • EP4345517B1 patent drawingFigure 1~2A
  • EP4345517B1 patent drawingFigure 2B~2C
  • EP4345517B1 patent drawingFigure 3~4

AI summary

A method forming a grating device includes: providing a substrate; entering the substrate into a process chamber; and depositing a grating material on the substrate to form a grating material layer on the substrate. A refractive index of the grating material gradually changes during depositing the grating material in the process chamber. The grating material layer includes a varying refractive index.