Waveguide Thickness Compensation on Polymer Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Manufacturing high-quality optical devices is challenged by the need to balance performance with cost, particularly when using substrates with significant thickness variations that lead to undesirable optical properties.
Innovation Solution
A method involving inkjet-based lithography to compensate for thickness variations in polymer substrates by applying a fluid drop pattern that corrects thickness irregularities, followed by curing, to create high-quality optical devices with customized thickness variations and diffraction gratings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low-cost polymer substrates are used for manufacturing optical devices, then manufacturing cost is reduced, but thickness variations and optical quality deteriorate
Solution Approach 1:
The patent applies preliminary action by measuring the substrate thickness profile before fabrication and using this information to pre-compensate for thickness variations. The system determines a drop pattern based on measured variations and applies fluid to compensate for thickness irregularities before the substrate is used for optical device fabrication, ensuring uniform thickness throughout the manufacturing process.
Solution Approach 2:
The patent applies local quality by implementing spatially varying fluid drop patterns that are specifically tailored to compensate for local thickness variations in different regions of the substrate. Instead of applying uniform treatment, the system varies the drop pattern locally based on the measured thickness profile, ensuring each region receives the appropriate compensation to achieve overall uniformity.
2Manufacturing precision
If traditional high-quality substrate materials are used, then optical performance is improved, but manufacturing cost increases
Solution Approach 1:
The patent applies this principle by using inexpensive polymer substrates instead of traditional expensive glass or crystal materials. The polymer substrates, while cheaper, are treated with thickness compensation techniques to achieve optical quality comparable to expensive materials, making high-quality optical devices more affordable to manufacture.
Solution Approach 2:
The patent applies parameter changes by modifying the physical and chemical properties of the polymer substrate through controlled fluid application and curing processes. By adjusting parameters such as fluid composition, drop pattern, and curing conditions, the substrate is transformed to have uniform thickness and improved optical properties, effectively changing the material characteristics to match high-quality standards.
3Manufacturing precision
If thickness compensation is applied to polymer substrates, then optical performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies mechanics substitution by replacing complex mechanical thickness control mechanisms with a fluid-based compensation system. Instead of using complex mechanical processing to achieve uniform thickness, the system uses measured thickness data to control fluid drop patterns, which then compensate for variations through chemical and physical processes during curing, simplifying the overall manufacturing approach.
Solution Approach 2:
The patent applies feedback by implementing a closed-loop system where the substrate thickness is measured, the measured variations are used to determine a compensation drop pattern, and the fluid is applied accordingly. This feedback mechanism ensures that thickness uniformity is continuously monitored and adjusted, automating the compensation process and reducing manual intervention while maintaining precision.
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
Enables the fast and low-cost fabrication of optical devices with improved optical performance, such as increased field of view and reduced manufacturing costs, using flexible polymer substrates like polycarbonate.
Implementation Method 1
curing the fluid includes one or more of applying ultraviolet radiation to the dispensed fluid, or applying heat to the dispensed fluid
Data Source
AI summary
This disclosure describes techniques for fabrication of waveguides as optical devices or for use in optical devices, with the waveguides customized to have a desired thickness variation. Techniques can employ inkjet-based lithography to compensate for thickness variations in the substrate used to manufacture the optical devices, and/or create custom variations in the thickness to achieve various optical properties in the resulting device. In some implementations, a curvature can also be applied to one or both surfaces of the substrate, to achieve desired optical performance and/or enhance fit of a wearable optical device. The optical devices created using the techniques described herein are suitable for use in virtual reality, augmented reality, and/or other suitable optical applications. The optical devices may be created on flexible (e.g., polymer) or more rigid (e.g., glass) substrates, with the thickness of the substrate being customizable using a jettable and curable polymer resin or photoresist.