Evanescent Waveguide Substrates for Illumination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current analytical systems face challenges in providing precise and controlled illumination over large areas, particularly in the z-axis, while minimizing illumination of non-relevant regions and reducing auto-fluorescence noise, which affects the accuracy of analyses such as DNA arrays and molecular interactions.
Innovation Solution
The use of substrates with surface-exposed optical waveguides that exploit evanescent fields to deliver focused illumination to discrete regions, eliminating the need for a cladding layer and reducing background illumination, thereby enhancing control over the illumination volume and minimizing auto-fluorescence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If wide area illumination is used to interrogate large numbers of analytical features, then the area of substrate illuminated is improved, but the precision of illumination control in the z-axis deteriorates
Solution Approach 1:
The illumination system is segmented into multiple independent waveguide elements, each capable of delivering light to a specific location on the substrate. This allows selective activation of individual waveguides to illuminate only the required area, maintaining precision while enabling flexible area coverage.
Solution Approach 2:
Each waveguide provides localized illumination with controlled evanescent field decay in the z-axis direction. The illumination intensity is naturally confined to a specific depth range, providing precise z-axis control at each illuminated location while allowing multiple locations to be addressed.
2Area of stationary object
If conventional illumination methods are used to illuminate large areas, then the area of substrate illuminated is improved, but auto-fluorescence noise increases
Solution Approach 1:
By segmenting the illumination into discrete waveguide locations, only the specific areas requiring analysis are illuminated. This minimizes the total illuminated volume and reduces background auto-fluorescence from surrounding regions, improving signal-to-noise ratio.
Solution Approach 2:
The evanescent field provides highly localized illumination that decays exponentially with distance from the waveguide surface. This confines excitation light to the immediate vicinity of the substrate, minimizing illumination of surrounding areas and reducing background fluorescence noise.
3Reliability
If cladding layers are used in waveguide structures, then the waveguide structure is completed, but the complexity of the device increases
Solution Approach 1:
The cladding layer is extracted or removed from the waveguide structure, allowing direct access to the core evanescent field at the substrate interface. This simplifies the overall device architecture while maintaining the essential waveguide functionality for controlled light delivery.
Solution Approach 2:
The waveguide core itself provides the necessary optical confinement and evanescent field generation without requiring an additional cladding layer. The substrate-w waveguide interface naturally produces the required field distribution, eliminating the need for complex multi-layer structures.
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 allows for efficient, spatially focused illumination with reduced noise, enabling precise analysis of surface-bound materials and improving the accuracy of assays by confining light to specific areas and reducing interference from surrounding environments.
Implementation Method 1
an analyte disposed sufficiently proximal to the first surface and external to the waveguide, to be illuminated by an evanescent field emanating from the waveguide when light is passed through the waveguide
Data Source
AI summary
Substrates, systems and methods for analyzing materials that include waveguide arrays disposed upon or within the substrate such that evanescent fields emanating from the waveguides illuminate materials disposed upon or proximal to the surface of the substrate, permitting analysis of such materials. The substrates, systems and methods are used in a variety of analytical operations, including, inter alia, nucleic acid analysis, including hybridization and sequencing analyses, cellular analyses and other molecular analyses.