Concurrent Laser Irradiation for Diffractive Optical Structure Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for manufacturing diffractive optical elements are sequential and lack concurrent light irradiation during growth, limiting the control over physicochemical properties and structural changes in the deposited material, which affects their performance and stability.

Innovation Solution

A light-assisted method where a continuous laser beam with a spatial intensity distribution, following Fresnel zones, is used to concurrently irradiate the deposit area during the growth of semiconductor compounds on a substrate, controlling the morphology and inducing diffractive structures with high spatial frequency, combining refractive and diffractive functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If sequential manufacturing methods are used for diffractive optical elements, then the process is simpler and more established, but control over physicochemical properties and structural changes during deposition is limited

Engineering Contradiction:
Improvecontrol over physicochemical propertiesVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines material deposition and light-assisted structural modification into a single concurrent process. The laser irradiation is applied during the deposition itself rather than in a separate subsequent step, allowing real-time control over the physicochemical properties and diffractive structure formation in the deposited layer.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The useful action of light irradiation continues throughout the entire deposition process rather than being applied separately before or after. This continuous concurrent action enables dynamic control over the formation of diffractive structures as the material is being deposited, improving precision over the sequential approach.

Inventive Principle:
Principle #20Continuity of useful action

2Manufacturing precision

If concurrent light irradiation is applied during deposit growth, then control over diffractive structures and optical properties is improved, but the system complexity and process difficulty increase

Engineering Contradiction:
Improvecontrol over diffractive structuresVSAvoidease of manufacture
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The deposited layer serves multiple functions simultaneously: it acts as the optical element substrate, the diffractive structure medium, and the functional optical component itself. The concurrent light-assisted deposition process achieves both material formation and structural patterning in one operation, reducing the need for separate manufacturing steps.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent controls diffractive structure formation by varying light irradiation parameters (intensity, wavelength, temporal profile) during deposition. By changing these parameters, different structural outcomes and optical properties can be achieved, providing precise control over the final element characteristics while maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If light-assisted deposition is used to create diffractive structures, then optical transparency and damage threshold are enhanced, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveoptical transparency and damage thresholdVSAvoidmanufacturing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical or thermal post-processing methods for creating diffractive structures with a light-assisted deposition process. The optical field directly controls the formation of diffractive structures during deposition, substituting subsequent mechanical machining or thermal treatment steps with an optical field-based approach during the deposition itself.

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

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 method enhances the optical transparency and damage threshold of the resulting optical elements by over an order of magnitude, enabling the creation of stable diffractive structures with improved performance and extended functionality.

Implementation Method 1

bringing about the vaporisation or sublimation of the starting material

Methodology Applied
Scientific EffectVapour phase generation: Evaporation

Implementation Method 2

The vapour phase, or plasma plume, that is generated condenses on a substrate located in the proximity of the starting material

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

Concurrent illumination of the deposit during its growth affects the physicochemical properties of the material that forms said deposit as a consequence of its effect on the structure of the material being formed

Methodology Applied
Scientific EffectLight-induced structural modification: Photopolymerisation

Implementation Method 4

a continuous laser beam with a wavelength of 532 nm and a spatial light intensity distribution with its phase following a pattern of Fresnel zones

Methodology Applied
Scientific EffectFresnel diffraction: Fresnel Diffraction

Data Source

PatentEP1990441B1Method and apparatus for registering diffractive optical structures
Publication Date: 2012.01.04 UNIV DE CADIZ
  • EP1990441B1 patent drawingFigure 1(a)~1(c)
  • EP1990441B1 patent drawingFigure 2
  • EP1990441B1 patent drawingFigure 3(a)~3(d)

AI summary

The invention relates to a method and apparatus for registering diffractive optical structures. More specifically, the invention relates to a simple, cost-effective method for producing diffractive optical elements. Said method includes the following steps in which: (a) a transparent substrate is postioned next to a white material inside a chamber, (b) the white material is vapourised or sublimated, (c) said vapour phase is deposited on the substrate, and (d) the area of the substrate on which the vapour phase was deposited is irradiated concurrently with a random distribution of the light intensity. The deposit has a diffractive optical functionality owing to the local changes produced in the structure thereof, which are controlled by the distribution of the light intensity used in the production process.