Compact Laser Assembly With Free-Space PCB-to-PIC Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical communication technologies face challenges in manufacturing compact pluggable optical modules due to the complexity and cost of using optical fibers for connectivity, alignment errors, and thermal management issues, particularly in direct coupling of optical sources to photonic integrated circuits.
Innovation Solution
A compact laser assembly is designed with a thermo-electric cooler disposed above a printed circuit board, where the optical train is positioned between the board and the cooler, allowing for direct coupling via free space and efficient heat extraction, reducing the need for fiber connections and improving thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical fibers are used for connectivity between lasers and photonic integrated circuits, then light transmission is effective, but manufacturing complexity and cost increase
Solution Approach 1:
The patent removes optical fibers from the system entirely, extracting the light transmission function directly into free-space propagation. The laser assembly makes direct optical contact with the photonic integrated circuit through a window in the substrate, eliminating the need for fiber coupling and associated alignment complexity.
Solution Approach 2:
The substrate acts as an intermediary component that provides both mechanical support and optical functionality. By creating a window in the substrate, it enables direct optical coupling between the laser and photonic circuit while maintaining structural integrity, replacing the need for fiber optic intermediaries.
2Reliability
If optical fibers are used for connectivity, then light transmission is achieved, but assembly process becomes labor intensive and prone to fiber breakage
Solution Approach 1:
The patent eliminates fibers from the assembly process entirely. The laser assembly is mounted directly to the substrate with the optical train positioned to couple light directly to the photonic integrated circuit through the substrate window, removing all fiber handling, termination, and coupling steps.
Solution Approach 2:
The system is segmented into distinct functional modules: the laser assembly as a separate unit that mounts to the substrate, and the photonic integrated circuit mounted on the same substrate. This modular approach simplifies assembly by allowing independent fabrication and testing of each module before final integration.
3Device complexity
If direct coupling of lasers to photonic integrated circuits is implemented, then fiber usage is reduced and manufacturing costs decrease, but precise alignment and opto-mechanical stability become critical challenges
Solution Approach 1:
The laser assembly and photonic integrated circuit are merged into a single planar structure on the substrate. Both components are mounted on the same substrate plane, with the laser positioned directly above the photonic circuit through the window, ensuring inherent alignment and mechanical stability without requiring complex alignment procedures.
Solution Approach 2:
The laser assembly is pre-positioned and secured to the substrate before final assembly completion. The mounting structure includes pre-formed alignment features and mechanical constraints that maintain precise positioning throughout subsequent assembly steps and operation.
4Device complexity
If traditional PCB designs with cavities or shortened lengths are used for direct coupling, then mechanical stress sensitivity increases, but thermal management remains critical
Solution Approach 1:
The patent extracts the laser assembly from traditional PCB mounting approaches. Instead of creating cavities or modifying PCB length, the laser is mounted directly on the substrate surface with the optical train positioned through a window, eliminating complex PCB structural modifications while maintaining mechanical stability.
Solution Approach 2:
The substrate serves multiple functions simultaneously: it provides mechanical support for both the laser assembly and photonic integrated circuit, enables optical transmission through the window, and facilitates thermal management by conducting heat away from the laser and photonic components to the substrate base.
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 design simplifies assembly, reduces manufacturing costs, enhances alignment precision, and improves thermal stability, resulting in more efficient and cost-effective optical communication devices.
Implementation Method 1
the thermo-electric cooler is configured to extract heat from the optical train outwardly from the printed circuit board
Implementation Method 2
The laser can be coupled with a ceramic carrier, a collimating lens, and an isolator. Such a device can be assembled on a printed circuit board main assembly, notably with the thermo-electric cooler disposed away or on top of the assembly. The device can be aligned with a photonic integrated circuit and can be functionally coupled therewith
Data Source
AI summary
A laser assembly is provided. The laser assembly includes a printed circuit board; a laser sub-assembly including a thermo-electric cooler and an optical train, wherein the laser sub-assembly is configured to connect to the printed circuit board such that the optical train is disposed between the printed circuit board and the thermo-electric cooler, wherein the thermo-electric cooler is configured to extract heat from the optical train outwardly from the printed circuit board, and wherein the laser assembly is configured to connect optically with a photonic integrated circuit via free space. Advantageously, the laser assembly includes a top-down approach where the thermo-electric cooler radiates heat outward, supports a pre-assembled approach, and uses free space connectivity for the laser path to the photonic integrated circuit, i.e., no fiber connections.