Diffractive Optical Element With Non-Interfering Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional diffractive optical elements (DOE) are limited in generating close meshed far field distributions due to interference issues between diffraction orders, which restricts their application in LIDAR systems and other fields where precise beam shaping is required.
Innovation Solution
A DOE comprising at least two diffractive structures with differing functionalities, designed to generate diffraction patterns that do not interfere with each other in the far field when irradiated with incoherent laser light, allowing for the creation of a uniform, close meshed far field distribution by superimposing individual diffraction patterns without mutual interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single diffractive structure is used to generate far field distributions, then the manufacturing cost is low and the structure is simple, but the density of individual features in the far field is limited due to interference between diffraction orders
Solution Approach 1:
The patent divides a single diffractive structure into multiple separate diffractive structures (at least two), each generating diffraction patterns that do not interfere with each other in the far field. This segmentation allows higher density of individual features by combining multiple non-interfering patterns, resolving the contradiction between feature density and structural simplicity.
2Manufacturing precision
If multiple diffractive structures are combined to increase feature density, then the density of individual features improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent assigns different local functionalities to different diffractive structures, where each structure is optimized for specific diffraction orders or spatial frequencies. This local specialization allows each structure to be manufactured with standard precision while achieving superior overall uniformity through their combined non-interfering patterns.
3Manufacturing precision
If diffractive structures are designed to generate close meshed far field distributions, then the feature density increases, but interference effects between diffraction orders deteriorate the uniformity
Solution Approach 1:
The patent extracts and separates the interfering diffraction orders into different diffractive structures, where each structure generates patterns at different spatial frequencies or angular ranges. By taking out the interfering components and placing them in separate structures, the patent achieves high feature density without the uniformity-deteriorating interference effects.
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 enables the generation of a shared uniform far field distribution with sharp edge drops, suitable for LIDAR systems and other applications, by maximizing the density of individual features in the overall diffraction pattern and minimizing interference effects, thus overcoming the limitations of conventional DOE designs.
Implementation Method 1
diffractive structures (12, 14, 16, 18) designed to generate diffraction patterns (32, 34, 36, 38) that do not interfere with one another in the far field as an overall diffraction pattern (30)
Data Source
AI summary
A diffractive optical element includes at least two diffractive structures situated next to one another, having differing functionalities, and being configured to, responsive to being irradiated independently of one another with incoherent laser light from beams of their respectively coupled laser sources, generate respective diffraction patterns that do not interfere with one another and that combine as an overall diffraction pattern in a far field. A method is provided for manufacturing such a diffractive optical element.