Rutile TiOx Optical Layer Stack for Low-Loss AR Image Overlay
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Solution Overview
Problem
Existing optical devices face challenges in effectively overlaying virtual images on ambient environments, particularly in augmented reality systems, due to issues with optical interference and loss in multi-phase titanium oxide layers.
Innovation Solution
A method involving the deposition of a titanium-containing layer on a substrate, followed by thermal treatment to form an orientation liner, and then depositing a titanium oxide layer exclusively in the rutile phase, which serves as a growth template to minimize optical interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a titanium oxide layer is deposited directly on a substrate without thermal treatment, then the deposition process is simpler and faster, but the optical loss increases due to mixed phases of titanium oxide
Solution Approach 1:
The patent applies preliminary action by performing thermal treatment on the substrate before depositing the titanium oxide layer. This pre-treatment prepares the substrate surface to promote exclusive formation of the desired rutile phase, thereby preventing optical loss issues that would arise from mixed phases. The thermal treatment is done in advance to ensure the correct crystal phase forms during subsequent deposition.
2Manufacturing precision
If thermal treatment is applied to create an orientation liner, then the crystal phase purity improves to 100% rutile phase, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The patent utilizes parameter changes by carefully controlling thermal treatment parameters (temperature, atmosphere, duration) to achieve the desired crystal phase transformation. By optimizing these parameters, the process efficiently produces 100% rutile phase titanium oxide without requiring excessively long treatment times or overly complex multi-step procedures.
3Reliability
If mixed phases of titanium oxide are present in the optical device film layer, then the deposition process is simpler, but the optical performance deteriorates due to high optical loss
Solution Approach 1:
The patent introduces an orientation liner as an intermediary layer between the substrate and the titanium oxide film. This orientation liner, created through thermal treatment, acts as a mediator that guides the formation of exclusively rutile phase titanium oxide during deposition. The intermediary layer ensures reliable optical performance by preventing mixed phase formation without significantly complicating the overall manufacturing process.
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 rutile phase titanium oxide layer reduces optical loss to as low as 0.03% compared to 0.07% or higher in multi-phase layers, enhancing the clarity and efficiency of virtual image overlay.
Implementation Method 1
thermally treating the titanium containing layer to form an orientation liner on the substrate
Implementation Method 2
depositing a titanium containing layer on a substrate and thermally treating the titanium containing layer to form an orientation liner on the substrate. Then, an optical device layer of titanium oxide is deposited over the orientation liner
Data Source
AI summary
Embodiments of the present disclosure generally relate to optical devices. More specifically, embodiments described herein relate to an optical device layer stack, an optical device formed from the optical device layer stack, and a method of forming an optical device layer stack.