Fusion-Spliced Fiber Interface for Laser Feedback Light Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-power fiber lasers face the issue of feedback light, which is deviated from the original transmission direction, leading to resource waste and potential damage to internal components, as existing methods either deviate the feedback light or fail to fully utilize it.
Innovation Solution
Fusion-splicing a target fiber to an output fiber with a lower refractive index core, ensuring total reflection of feedback light at the fusion-splicing surface, preventing it from entering the output fiber and the resonant cavity, thereby maintaining normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the end face of the fiber is tilted at an 8-degree angle to reduce feedback light, then the return loss is increased, but the feedback light is deviated from the original transmission direction leading to resource waste
Solution Approach 1:
The patent changes the refractive index parameter by using fluorine-doped silica core in the output fiber (lower refractive index) and germanium-doped silica core in the target fiber (higher refractive index). This parameter change enables total internal reflection of feedback light at the fusion splicing interface while maintaining proper light transmission direction, thus improving return loss without causing resource waste
2Reliability
If a serrated grain is made on the end cap cone surface to break the smooth interface, then feedback light coupling into the fiber is reduced, but the feedback light transmission direction is deviated resulting in resource waste
Solution Approach 1:
Instead of changing the physical surface structure (serrated grain), the patent changes the optical parameter (refractive index) by using fluorine-doped silica core for the output fiber and germanium-doped silica core for the target fiber. This creates total internal reflection at the fusion splicing interface, reducing feedback light coupling while maintaining proper light transmission direction
3Reliability
If feedback light is deviated from the original transmission direction, then the feedback light cannot continue to be transmitted in the core, but the feedback light cannot be fully utilized resulting in resource waste
Solution Approach 1:
The patent uses refractive index parameter change (fluorine-doped silica core with lower refractive index in output fiber, germanium-doped silica core with higher refractive index in target fiber) to create total internal reflection. This prevents feedback light from entering the output fiber while redirecting it along the transmission direction, thus protecting the laser without wasting energy
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
Effectively prevents feedback light from entering the output fiber and resonant cavity, ensuring the normal operation of the laser's internal components and reducing resource waste by redirecting feedback light along the transmission direction.
Implementation Method 1
total reflection occurs due to refractive index difference on the fusion-splicing surface
Implementation Method 2
refractive index of a core of the output fiber of the laser is less than the refractive index of a core of the target fiber
Data Source
AI summary
A method for preventing feedback light of a laser, includes fusion-splicing a target fiber to an output fiber of a laser, so that laser lights generated by the laser are output from the target fiber. A refractive index of a core of the output fiber of the laser is less than a refractive index of a core of the target fiber. When a feedback light of a laser light of the laser is reversely transmitted to a fusion-splicing surface through the target fiber, total reflection occurs due to a refractive index difference on the fusion-splicing surface, so that the feedback light is transmitted along the transmission direction of the laser light, and is prevented from entering the output fiber along the reverse direction of the laser light and further entering the laser's resonant cavity to damage the laser component or burn out the gain fiber.