Optical Coupling Between Integrated Circuit Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical coupling methods in integrated circuit devices face limitations in scalability, compactness, optical coupling efficiency, and electrical crosstalk, especially as vertical spacing between layers increases, leading to issues with alignment, complexity, and fabrication costs.
Innovation Solution
The method involves evanescent and projectable coupling of optical signals between a photonic crystal defect waveguide and cavity in one layer and an optical aperture in another layer, utilizing a photonic crystal structure with a defect waveguide and cavity to facilitate efficient vertical optical communication, potentially with the aid of lensing elements for enhanced coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If vertical optical coupling schemes are used to reduce footprint and accommodate more interconnections, then device compactness and interconnection capacity are improved, but optical coupling efficiency decreases and optical crosstalk increases as vertical spacing increases
Solution Approach 1:
The patent introduces an optical coupling structure comprising lens elements and aperture elements as intermediaries between the optical signal source on the first chip and the detector on the second chip. The lens elements focus and redirect optical signals, while the aperture elements control light propagation paths, thereby maintaining efficient optical coupling even at increased vertical spacing between chips.
Solution Approach 2:
The patent transitions from edge-facet coupling (lateral dimension) to vertical coupling schemes, utilizing the vertical dimension for optical signal transmission. This dimensional change allows for reduced footprint and increased interconnection capacity while managing optical coupling through carefully designed lens and aperture configurations in the vertical path.
2Adaptability or versatility
If vertical spacing between facing layers is increased to accommodate device design, then device flexibility is improved, but optical coupling efficiency decreases and alignment issues worsen
Solution Approach 1:
The optical coupling structure with lens elements and aperture elements acts as an intermediary system that compensates for alignment tolerances. The lens elements provide focal point convergence that is less sensitive to lateral misalignment, and the aperture elements define precise light paths that maintain coupling efficiency despite variations in vertical spacing and positional alignment.
3Ease of manufacture
If edge facet abutment is used for optical coupling, then fabrication simplicity is improved, but scalability and device compactness are limited
Solution Approach 1:
The patent moves from lateral edge-facet coupling to vertical coupling architecture, enabling multiple optical interconnections between facing chips. This vertical arrangement allows for increased interconnection density and scalability while maintaining compact device footprint, as multiple signal paths can be established through the vertical optical coupling structure.
4Adaptability or versatility
If optical fiber is used to transfer signals between edge facets, then coupling flexibility is improved, but device complexity and fabrication cost increase
Solution Approach 1:
The patent extracts the optical fiber from the coupling mechanism and replaces it with integrated lens and aperture elements formed directly on the chip structures. This elimination of external optical fibers simplifies the overall device architecture, reduces fabrication complexity and cost, while maintaining the necessary optical signal transfer capability between chips.
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 enhances optical coupling efficiency and scalability while reducing lateral area requirements and complexity, allowing for more compact and efficient interconnections between integrated circuit layers, even at increased vertical spacing.
Implementation Method 1
The optical signal is evanescently coupled between a photonic crystal defect waveguide and a photonic crystal defect cavity in the first integrated circuit layer
Implementation Method 2
projectably coupled between the photonic crystal defect cavity and an optical aperture on the second integrated circuit layer
Data Source
AI summary
In an integrated circuit device comprising a vertical arrangement of integrated circuit layers, coupling of an optical signal between a first integrated circuit layer thereof and a second integrated circuit layer thereof is described. The optical signal is evanescently coupled between a photonic crystal defect waveguide and a photonic crystal defect cavity in the first integrated circuit layer and projectably coupled between the photonic crystal defect cavity and an optical aperture on the second integrated circuit layer.