Hologram Coupling into Waveguide via Spatial Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing holographic projection systems face challenges in efficiently coupling holographic wavefronts into waveguides, particularly in multiplexing multiple holograms without significant light loss.
Innovation Solution
The system employs a waveguide pupil expander with an input port that includes multiple input areas for receiving holographic wavefronts from different channels. By appropriately positioning these input areas and using internal reflections within the waveguide, the system achieves efficient coupling and multiplexing of holographic wavefronts without the need for additional optical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple holographic wavefronts are coupled into a waveguide using conventional methods, then multiplexing of multiple channels is achieved, but significant light loss occurs
Solution Approach 1:
The patent positions multiple holographic wavefronts at different longitudinal positions along the waveguide length rather than attempting to combine them at a single transverse plane. This longitudinal spatial separation allows each wavefront to be coupled independently through dedicated input areas, eliminating the need for complex beam combining optics and preventing light loss that would occur from multiple reflections and interference at a single coupling plane.
Solution Approach 2:
The input port of the waveguide is divided into multiple spatially separated input areas, with each input area dedicated to receiving a specific holographic wavefront from a different channel. This segmentation allows independent coupling of multiple wavelengths without interference, as each wavelength is introduced at a separate location along the waveguide length, thereby maintaining high optical efficiency while achieving multi-channel multiplexing.
2Productivity
If additional optical components are used to combine multiple channels, then coupling efficiency may improve, but device complexity increases
Solution Approach 1:
The waveguide structure itself provides the functionality of combining multiple channels through its inherent longitudinal geometry and multiple input areas. The waveguide acts as its own coupling mechanism, utilizing its own structure to receive and guide multiple holographic wavefronts from different channels without requiring external beam combining optics, thereby maintaining high coupling efficiency while minimizing device complexity.
Solution Approach 2:
The patent merges the functions of multiple optical components into a single integrated waveguide structure. By positioning multiple input areas along the length of the waveguide, the system combines multiple holographic wavefronts within the waveguide itself rather than using separate beam combining optics, achieving both high coupling efficiency and reduced device complexity through functional integration.
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 optically efficient coupling of holographic wavefronts into the waveguide, allowing for the multiplexing of multiple channels with minimal light loss, and facilitates the creation of full-color holographic projections using a single display device.
Implementation Method 1
the first holographic wavefront can be made to reflect (internally within the waveguide) on a portion of a surface of the waveguide that is aligned with the second input area
Data Source
AI summary
A holographic projection system is provided. The holographic projection system includes a first hologram and a second hologram. The holographic projection system is arranged to spatially modulate light in accordance with the first hologram to form a first holographic wavefront and to spatially modulate light in accordance with the second hologram to form a second holographic wavefront. The holographic projection system further includes a waveguide including an input port that includes a first input area arranged to receive the first holographic wavefront and a second input area arranged to receive the second holographic wavefront. The waveguide further includes a pair of surfaces arranged to waveguide the first and second holographic wavefront therebetween. The waveguide is arranged such the first holographic wavefront is combined with the second holographic wavefront after one or more internal reflections of the first holographic wavefront between the pair of surfaces.