Lens Assembly for Photonic Integrated Circuit Optical Coupling
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Solution Overview
Problem
Efficient and cost-effective alignment of optics to couple light into and out of photonic integrated circuits (PICs) is challenging, with existing methods being either expensive or low-yield.
Innovation Solution
A lens assembly is secured to the PIC die, with parts extending over the top surface and aligned using a pick-and-place machine, then epoxied in place, allowing for relaxed alignment tolerances and improved yield by testing individual dies before packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If V-grooves are used to align fiber connector or lens are attached to PIC, then optical coupling efficiency is improved, but manufacturing cost increases and yield decreases
Solution Approach 1:
The patent implements preliminary testing of individual PIC dies before packaging by integrating test structures directly into the PIC fabrication process. This allows faulty dies to be identified and discarded early, preventing waste of packaging resources on defective units and improving overall manufacturing yield while maintaining optical coupling efficiency through pre-validated components
2Manufacturing precision
If V-grooves are used to align fiber connector or lens are attached to PIC, then optical coupling efficiency is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent merges the optical coupling function directly into the PIC device by integrating optical interfaces and coupling structures during the semiconductor fabrication process itself. This consolidation eliminates the need for separate, expensive alignment and assembly operations, reducing manufacturing complexity and cost while achieving the required optical coupling efficiency through precision fabrication techniques
3Productivity
If lens assembly is secured to PIC die with extended alignment, then alignment tolerance is relaxed and yield improves, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary alignment structure that mediates between the lens assembly and the PIC die. This intermediate element provides mechanical support and alignment references, allowing the lens to be positioned with relaxed tolerances while maintaining precise optical alignment. The intermediary structure absorbs the complexity of alignment, simplifying the overall manufacturing process and improving yield
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 facilitates efficient optical coupling with relaxed alignment requirements and improves the yield of packaged PICs by discarding faulty dies during the testing process.
Implementation Method 1
a lens assembly, wherein the lens assembly comprises one or more lenses, wherein individual lenses of the one or more lenses are positioned to focus light that comes from corresponding waveguides
Data Source
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AI summary
Technologies for optical coupling to photonic integrated circuit (PIC) dies are disclosed. In the illustrative embodiment, a lens assembly with one or more lenses is positioned to collimate light coming out of one or more waveguides in the PIC die. Part of the illustrative lens assembly extends above a top surface of the PIC die and is in contact with the PIC die. The top surface of the PIC die establishes the vertical positioning of the lens assembly. In the illustrative embodiment, the lens assembly is positioned at least partially inside a cavity defined within the PIC die, which allows the lens assembly to be integrated at the wafer level, before singulation into individual dies.