Optical Fiber Combiner Packaging for High-Power Laser Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-power optical fiber combiners in laser applications face reliability issues due to heat management challenges, particularly when exposed to temperature and humidity, leading to degradation of polymer coatings and potential damage from localized hot spots, especially when immersed in cooling water.
Innovation Solution
A water-cooled packaging scheme for optical fiber combiners that uses a combiner mount with U-grooves and epoxies of varying refractive indices to effectively disperse heat without immersing the combiner in cooling water, ensuring thermal conductivity and minimizing stress-induced degradations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the optical fiber combiner is immersed in cooling water to manage heat, then heat dissipation is improved, but the polymer coating degrades due to water exposure and humidity leading to reliability issues
Solution Approach 1:
The patent divides the thermal management function into separate components: a heat sink attached to the combiner mount that contacts water, while the combiner itself remains dry. This segmentation allows heat dissipation without direct water exposure to the polymer coating.
Solution Approach 2:
The patent introduces an intermediary thermal interface between the combiner and cooling water. The combiner mount with U-grooves and heat sink acts as a mediator that transfers heat away from the combiner without requiring the combiner to be immersed in water, thus protecting the polymer coating.
2Temperature
If the optical fiber combiner is exposed to temperature and humidity environment, then cooling efficiency is improved, but the low refractive index coating degrades and allows OH ingression into the glass core
Solution Approach 1:
The patent extracts the harmful exposure to temperature and humidity from the combiner system by directing cooling water to contact only the heat sink and mounting structure, not the optical fiber combiner itself. This removes the source of coating degradation and OH ingression while maintaining cooling efficiency.
3Power
If the polymer coating is exposed to high thermal load, then heat dissipation capacity is improved, but the coating tolerance is exceeded leading to localized hot spots and catastrophic burns
Solution Approach 1:
The patent transitions from direct thermal contact between water and the combiner to a dimensional separation where cooling occurs through the mount structure. This spatial reorganization allows heat dissipation without concentrating thermal stress on the polymer coating, preventing localized hot spots.
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 solution maintains long-term reliability and beam quality by efficiently dispersing heat and preventing optical losses, while avoiding water exposure that can degrade the optical fiber combiner, thus enhancing the performance of high-power fiber lasers.
Implementation Method 1
The three epoxies with different refractive indices not only fix the optical fiber combiner in place but also serve thermal conductive contacts to effectively disperse the heat generated in the optical fiber combiner to the combiner mount
Implementation Method 2
The three epoxies with different refractive indices accommodated in the three areas not only fix the optical fiber combiner in place but also serve thermal conductive contacts
Data Source
AI summary
A water-cooled package of an optical fiber combiner (OFC) comprising an OFC assembly, a front end cap (EC), a rear EC, and a housing operates for long term reliability. The OFC assembly comprises two submounts and an OFC. Each of the two submounts comprises a U-groove in a lengthwise direction and two flat portions symmetrically connected to the U-groove in a widthwise direction. The two flat portions of each of the two submounts are mechanically coincident in a way to form a cavity between the two U-grooves of the two submounts, in which the OFC is fixed. When the OFC assembly is concentrically mated and sealed with the front EC and the rear EC, cooling water in the water-cooled package is prevented from immersing the OFC. The configurations can minimize varying stress-induced optical degradations and maintain beam quality of a laser light exiting the OFC.