Waveguide Concentrator Layout for Compact Near-Eye Beam Collimation
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Solution Overview
Problem
Existing wearable display technologies face challenges in compactly and efficiently collimating light beams from semiconductor light sources for near-eye displays, particularly in achieving well-defined spatial beam characteristics for multi-color output, which is essential for virtual and augmented reality applications.
Innovation Solution
A waveguide concentrator system is introduced, comprising a substrate with waveguides that receive optical beams from semiconductor light sources, forming a 2D or 3D array of output ports, and optionally including a microlens array and inter-layer couplers, to collimate and redirect light beams effectively, allowing for compact packaging and thermal decoupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional collimation methods are used for semiconductor light sources, then light beam collimation is achieved, but the system size becomes large and thermal management becomes difficult
Solution Approach 1:
The patent transitions from conventional 2D planar collimation to 3D waveguide-based collimation. The waveguides extend in the third dimension (depth) to achieve collimation, allowing compact lateral footprint while maintaining effective collimation distance. This dimensional transition resolves the contradiction between compact size and collimation efficiency.
Solution Approach 2:
The waveguide structure acts as an intermediary between the semiconductor light source and the external optical system. It mediates the collimation function by guiding and shaping the light beams within its structured pathways, enabling compact integration while maintaining beam quality through the waveguide's inherent optical confinement and directional control.
2Adaptability or versatility
If multiple semiconductor light sources are integrated for multi-color output, then color display capability is improved, but thermal management becomes more challenging
Solution Approach 1:
The patent segments the light source system into multiple independent semiconductor light sources, each potentially emitting different wavelengths (colors). Each light source has its own waveguide pathways, allowing independent thermal management and optical control. This segmentation enables multi-color output while facilitating distributed thermal handling through the modular structure.
Solution Approach 2:
The waveguides are configured to extend in three dimensions, allowing vertical stacking of multiple light source-waveguide units. This 3D arrangement separates heat-generating components in the vertical dimension while maintaining compact lateral footprint, effectively managing thermal loads from multiple light sources through spatial distribution in the third dimension.
3Volume of moving object
If waveguide concentrator is used for collimation, then compactness is improved, but manufacturing complexity increases
Solution Approach 1:
The waveguide structure serves multiple functions simultaneously: it acts as the collimation medium, the structural support, and the thermal management pathway. This multi-functionality reduces the need for separate components, simplifying the overall manufacturing process despite the complexity of waveguide fabrication, as the same structure performs multiple critical roles.
Solution Approach 2:
The waveguide concentrator utilizes composite material structures combining different materials with complementary properties (e.g., high refractive index waveguide core with low refractive index cladding, or thermally conductive materials integrated with optical pathways). These composite structures enable simultaneous optimization of optical performance and manufacturability through established composite material fabrication techniques.
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
The waveguide concentrator system enables efficient collimation and redirection of light beams, improving the compactness and thermal management of light sources, simplifying interfacing with optical fibers, and enhancing the performance of near-eye displays by providing a compact, multi-color light source with reduced beam distortions.
Implementation Method 1
Each waveguide of the plurality of waveguides is configured for receiving an optical beam of the plurality of optical beams at the first end
Implementation Method 2
A waveguide concentrator is optically coupled to the light source subassembly. The waveguide concentrator includes a second substrate comprising first and second ends, and a plurality of waveguides each extending from the first end to the second end
Data Source
AI summary
A light source or projector for a near-eye display includes a light source subassembly optically coupled to a waveguide concentrator. The light source subassembly may include several semiconductor chips each hosting an array of emitters such s superluminescent light-emitting diodes. The semiconductor chips may be disposed side-by-side, with their emitting sides or facets coupled to the waveguide concentrator, which provides a tight array of output light ports on a common output plane of the concentrator. The output diverging beams at the array of output light ports are coupled to a collimator, which collimates the beams and couples them to an angular scanner for scanning the collimated light beams together across the field of view of the display.