Transparent Optical Interposer for Adiabatic PIC-to-Fiber Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing silicon photonic chip-to-fiber optical coupling schemes face challenges in achieving efficient and reliable alignment and communication between optical fibers and waveguides, particularly in adiabatic coupling, which is less dependent on wavelength and has relaxed mechanical tolerances.
Innovation Solution
An optically transparent interposer is introduced between the photonic integrated circuit and optical fibers, featuring adiabatic coupling regions and mode conversion regions to align and efficiently transfer optical signals, while also allowing for electrical signal routing through conductive vias and interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If edge coupling or surface coupling is used for optical fiber to waveguide alignment, then optical coupling is achieved, but mechanical tolerance is tight and wavelength dependence is high
Solution Approach 1:
An optically transparent interposer is introduced as an intermediary component between the silicon photonic chip and optical fibers. The interposer features adiabatic coupling regions that gradually transform the optical mode from the waveguide to the fiber, serving as a mediator that relaxes the tight mechanical tolerance requirements of direct coupling schemes while maintaining high optical coupling efficiency
Solution Approach 2:
The patent employs adiabatic coupling regions that gradually change the optical mode parameters (size, shape, and field distribution) along the propagation direction. This continuous parameter transformation allows the system to transition from waveguide mode to fiber mode with relaxed mechanical alignment tolerances and reduced wavelength dependence compared to abrupt coupling interfaces
2Manufacturing precision
If adiabatic coupling is used to relax mechanical tolerances, then mechanical tolerance is improved, but device complexity increases due to additional interposer structure
Solution Approach 1:
The optically transparent interposer is designed to perform multiple functions simultaneously: it provides adiabatic coupling for optical mode transformation, serves as a mechanical support structure for fiber array alignment, enables electrical signal routing through conductive vias, and facilitates thermal management. This multi-functionality reduces the need for separate components, thereby limiting the increase in overall device complexity while achieving relaxed mechanical tolerances
3Reliability
If fiber array is placed in optical alignment with waveguide array, then optical communication is achieved, but electrical signal routing becomes complex
Solution Approach 1:
The patent introduces a vertical dimension for electrical signal routing by incorporating conductive vias that extend through the thickness of the optically transparent interposer. This three-dimensional electrical interconnect architecture allows electrical signals to be routed independently from the planar optical fiber array alignment, decoupling the complexity of electrical signal routing from optical communication 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
The solution enables high-bandwidth communication with improved mechanical tolerance and reduced wavelength dependence, facilitating simultaneous optical and electrical communication with precise alignment and efficient mode size conversion between silicon photonics chips and optical fibers.
Implementation Method 1
a first waveguide of a first optical module, each having a respective adiabatic coupling region that is configured to adiabatically couple to a waveguide of another optical module
Implementation Method 2
An optically transparent interposer is introduced between the photonic integrated circuit and optical fibers, featuring adiabatic coupling regions and mode conversion regions to align and efficiently transfer optical signals
Data Source
Figure 1~2A
Figure 2B~2D
Figure 3~4B
AI summary
Waveguides of optically transparent interposers are adiabatically coupled to respective waveguides of photonic integrated circuits that are mounted to the optically transparent interposers. In particular, photonic integrated circuits can be mounted to an interposer that has both optical connections and electrical connections. The optical connections of the interposer can be adiabatically coupled to the photonic integrated circuit. The electrical connections can be connected to the photonic integrated circuit and to a host board that also supports an ASIC.