Adiabatic Optical Coupler for Direct SOI Interposer Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for coupling light from a waveguide into an interposer using a silicon nitride layer are complex and costly, necessitating a more efficient and cost-effective solution.
Innovation Solution
An adiabatic optical coupler with tapered regions and a sub-wavelength grating is used to directly couple light from a waveguide to an interposer, eliminating the need for a silicon nitride layer, and featuring a blunt tip design to facilitate manufacturing and reduce light loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a silicon nitride layer is used to couple light from waveguide to interposer waveguide, then optical coupling is achieved, but fabrication complexity and manufacturing cost increase
Solution Approach 1:
The patent removes the silicon nitride layer from the optical coupling structure and replaces it with a tapered silicon waveguide region. This extraction of the problematic intermediate layer simplifies the fabrication process while maintaining the optical coupling function through the tapered geometry alone.
Solution Approach 2:
The tapered waveguide region acts as an intermediary structure that enables optical coupling between the silicon waveguide and the interposer waveguide. The gradual taper provides smooth mode transition and refractive index matching without requiring the silicon nitride intermediate layer.
2Reliability
If a silicon nitride layer is used to couple light from waveguide to interposer waveguide, then optical coupling is achieved, but manufacturing cost increases
Solution Approach 1:
By removing the silicon nitride layer entirely and using only silicon-based structures with tapered geometries, the patent eliminates the need for specialized silicon nitride deposition processes, thereby reducing manufacturing cost while preserving optical coupling performance.
Solution Approach 2:
The patent changes the geometric parameters of the waveguide (introducing tapers with specific angle ranges) to achieve the optical coupling function that previously required the silicon nitride layer. This parameter-based solution uses standard silicon processing techniques, reducing cost.
3Device complexity
If a tapered waveguide structure is used to couple light directly, then manufacturing complexity is reduced, but light loss may increase
Solution Approach 1:
The patent optimizes the taper parameters (angle, length, and profile) to minimize light loss while maintaining manufacturing simplicity. The gradual taper geometry provides smooth mode transition that reduces scattering and reflection losses compared to abrupt transitions.
Solution Approach 2:
The use of curved or gradual tapered geometries instead of sharp angular transitions reduces optical losses by minimizing mode discontinuities. The smooth curvature of the taper profile enables adiabatic mode coupling with minimal scattering loss.
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 adiabatic optical coupler effectively matches the refractive index of the waveguide to the interposer, enabling efficient light transfer with reduced manufacturing complexity and costs, while maintaining low light loss.
Implementation Method 1
The adiabatic optical coupler effectively matches the refractive index of the waveguide to the interposer, enabling efficient light transfer
Implementation Method 2
An adiabatic optical coupler with tapered regions and a sub-wavelength grating is used to directly couple light from a waveguide to an interposer
Data Source
AI summary
An adiabatic optical coupler can include: a top tapered region that includes a top taper having two top tapered sides that taper from a first end region to a top tip region, the top taper having a first length; and a bottom tapered region under the top tapered region, wherein the bottom tapered region includes a bottom taper having two bottom tapered sides that taper from the first end region to a bottom tip region, the bottom taper having a second length that is longer than the first length. Another adiabatic optical coupler can include: a tapered region that includes a taper having two tapered sides that taper from an end region to a tip region; and a sub-wavelength grating (SWG) optically coupled with the tip region. Another adiabatic optical coupler can include a combination of these two adiabatic optical couplers.