Stacked Optical Waveguides for Multiple Focal Planes
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Solution Overview
Problem
Optical waveguides used in AR/MR applications are often limited to a single focal plane and have complex and expensive manufacturing processes, restricting their functionality and cost-effectiveness.
Innovation Solution
The use of multiple beam splitting elements within a substrate to create stacked optical waveguides, where light is reflected and transmitted between beam splitting elements, allowing for multiple focal planes and simplified manufacturing through surface contouring and coating techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple waveguides are stacked within a substrate to enable multiple focal planes, then the functionality and versatility of the optical system is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Multiple waveguides are nested within a single substrate, with each waveguide containing beam splitting elements that guide light through the substrate. The waveguides are positioned at different depths within the substrate, creating a nested configuration that enables multiple focal planes while maintaining a compact single-substrate structure
Solution Approach 2:
The patent transitions from traditional planar waveguide arrangements to a three-dimensional stacked configuration within the substrate. By positioning beam splitting elements and waveguides at different vertical depths within the substrate, the system adds a depth dimension to light propagation, enabling multiple focal planes and enhanced optical functionality
2Manufacturing precision
If traditional manufacturing methods are used for optical waveguides, then manufacturing precision can be maintained, but the ease of manufacture and production cost are worsened
Solution Approach 1:
Multiple waveguides and their associated beam splitting elements are manufactured simultaneously within a single substrate using integrated fabrication processes. The method combines substrate preparation, coating application, and waveguide formation into a unified manufacturing workflow, reducing the number of separate manufacturing steps and improving production efficiency
Solution Approach 2:
The substrate serves multiple functions simultaneously: it acts as the structural platform, the light-guiding medium, and the embedding matrix for beam splitting elements. This multi-functional design simplifies manufacturing by eliminating the need for separate components and assembly steps, while maintaining optical precision through the integrated structure
3Illumination intensity
If beam splitting elements are positioned to reflect light between waveguides, then the optical efficiency and image quality are improved, but the risk of light interference and crosstalk between waveguides increases
Solution Approach 1:
Beam splitting elements are positioned at specific local positions within the substrate at controlled distances from the front surface. Each beam splitting element is precisely positioned to reflect light from its associated waveguide toward the front surface without intersecting light paths from other waveguides. This localized positioning strategy ensures high optical efficiency while preventing light interference between adjacent waveguides
Solution Approach 2:
The substrate acts as an intermediary medium that separates and isolates light paths from different waveguides. By positioning beam splitting elements at different depths within the substrate, the substrate structure itself mediates between multiple light sources, preventing direct interaction and interference while allowing each waveguide to maintain its independent optical path
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 creation of optical waveguides that project images to multiple virtual image planes, enhancing functionality and reducing manufacturing complexity and costs, while maintaining image quality and avoiding light interference between waveguides.
Implementation Method 1
A light image injected at an edge of an eyepiece may be transmitted through total internal reflection to a waveguide that projects the light image to a viewer's eye
Data Source
AI summary
An optical apparatus is provided comprising: first and second optical waveguides disposed in a substrate such that light reflected by a beam splitting optical element of the first waveguide passes between beam splitting elements of the second waveguide.