3D Freeform Photonic Wire Bonds for Low-Loss Chip Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for connecting lateral single-mode integrated optical waveguides in silicon photonics face challenges due to high precision requirements and high optical losses, limiting integration density and scalability in photonic systems.
Innovation Solution
The development of photonic wire bonds (PWBs) with a refractive index contrast of at least 0.01, allowing for three-dimensional structuring and connection of optical waveguides outside the integration plane, enabling high integration densities and low-loss optical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard single-mode fibers are used for connecting integrated photonic systems with manual positioning methods, then optical connection is achieved, but integration density is low and packaging costs are high
Solution Approach 1:
The patent transitions from planar 2D waveguide connections to 3D spatial routing with freeform waveguide structures. The waveguides can extend in three dimensions with variable cross-sections, allowing connections between chips positioned at different heights and lateral locations, thereby increasing integration density without manual fiber positioning
Solution Approach 2:
The patent employs variable cross-sectional parameters of waveguides (changing width and height along propagation direction) to adapt mode fields for efficient coupling. This parameter variation enables automated manufacturing with standardized interfaces while maintaining low insertion losses, reducing packaging costs
2Reliability
If lateral single-mode waveguides with diameters below 1 μm are used, then optical connection precision is required, but adjustment techniques cannot meet the precision requirements
Solution Approach 1:
The patent incorporates mode field adaptation structures (such as tapered waveguides or lens structures) integrated directly with the waveguide before connection. This preliminary shaping of the mode field ensures that even sub-micrometer waveguides can be connected with relaxed precision requirements, enabling automated manufacturing
Solution Approach 2:
The waveguide cross-sectional parameters are varied along the propagation direction to transform the mode field distribution. This gradual parameter change adapts the confined single-mode field to a larger mode area for easier coupling, achieving high precision connections through automated processes
3Ease of operation
If multi-modal waveguides with large cross-sectional surfaces are used, then passive positioning methods work well, but connection to lateral single-mode waveguides is not possible
Solution Approach 1:
The patent uses variable cross-sectional waveguides that transition from large multi-modal cross-sections to small single-mode cross-sections along the propagation direction. This parameter transformation allows the waveguide to support multiple modes during passive positioning alignment, then confine to single-mode for the actual optical connection, combining benefits of both approaches
Solution Approach 2:
The patent employs 3D freeform waveguide structures with varying cross-sections in both lateral and vertical dimensions. This dimensional flexibility allows mode field transformation from multi-modal to single-mode while maintaining compatibility with passive positioning methods used in automated manufacturing
4Ease of manufacture
If direct fiber-to-waveguide connection is used, then connection is achieved, but insertion losses are high and mode field adaptation is difficult
Solution Approach 1:
The patent implements waveguides with continuously varying cross-sectional parameters (width, height, material composition) along the propagation direction. This gradual parameter change transforms the mode field from the waveguide mode to the fiber mode, achieving low insertion losses through automated direct connection without manual alignment
Solution Approach 2:
The variable cross-section waveguide structure acts as an intermediary between the integrated photonic circuit and the optical fiber. The changing parameters of the waveguide create a transition region that adapts the mode fields of both components, enabling efficient coupling with relaxed precision requirements
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
PWBs achieve low insertion losses (<2 dB) over a wide optical bandwidth, enabling efficient and cost-effective production of high-density photonic wire bonds for large-scale photonic systems.
Implementation Method 1
at least one optical waveguide planar integrated on the at least one planar substrate; optical connecting structure; and at least one optical waveguide structure having at least one end connected via the optical connecting structure to the at least one planar integrated optical waveguide
Implementation Method 2
a refractive index contrast between a core region and a cladding region of the at least one optical waveguide structure is at least 0.01
Data Source
AI summary
An optical arrangement includes a plurality of planar substrates with at least one planar integrated optical waveguide on each planar substrate. At least one optical waveguide structure has at least one end connected via an optical connecting structure to one of the planar integrated optical waveguides. The optical waveguide structure is positioned at least partly outside the integration plane for the planar integrated optical waveguide and a refractive index contrast between a core region and a cladding region of the optical waveguide structure is at least 0.01.