Cladless Pump Fiber Inputs for High NA Laser Combiners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fiber-based gain systems face limitations in efficiently coupling high numerical aperture (NA) pump light, leading to restricted power output and increased risk of fiber failure due to the architecture of tapered fiber bundles and glass-clad pump fibers, which restrict the number of pump fibers that can be combined and result in inefficient pump light coupling and energy loss.
Innovation Solution
A novel non-tapered high NA pump and signal combiner architecture that allows for the coupling of partitioned high NA pump light outside the lasing cavity, using a fat-fiber adapter to split and combine high NA pump light with a signal fiber, reducing the risk of fiber failure and increasing pump efficiency by introducing pump light within the lasing cavity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional tapered fiber bundles with glass-clad pump fibers are used, then the structure is simple and easy to manufacture, but the number of pump fibers that can be combined is limited and pump light coupling efficiency is reduced
Solution Approach 1:
The patent removes the glass cladding from pump fibers at the input end of the combiner, creating cladless pump fiber inputs. This extraction of the cladding layer allows pump light to be coupled directly into the gain fiber without being constrained by the numerical aperture limitations of glass-clad fibers, thereby enabling a greater number of pump fibers to be combined while maintaining system simplicity.
Solution Approach 2:
The invention changes the numerical aperture parameter of the pump fiber input by removing the glass cladding, transitioning from a constrained NA determined by the cladding to an unconstrained NA that allows direct coupling to the gain fiber. This parameter change enables higher pump light coupling efficiency and accommodates more pump fibers without increasing device complexity.
2Use of energy by moving object
If glass-clad pump fibers are used, then the fiber structure is protected and easy to handle, but pump light coupling efficiency is reduced and energy loss increases
Solution Approach 1:
By removing the glass cladding from pump fibers at the input interface, the patent eliminates the numerical aperture barrier that causes pump light energy loss. The cladless configuration allows direct coupling of pump light into the gain fiber core, maximizing coupling efficiency and minimizing energy loss while maintaining fiber protection in non-critical regions.
3Power
If tapered fiber bundles are used, then the combiner can be manufactured with standard processes, but the architecture restricts power output and increases risk of fiber failure
Solution Approach 1:
The patent removes glass cladding from pump fibers in the high-stress input region where pump light is coupled, eliminating the interface between cladding and gain fiber that creates stress concentration points. This reduces the risk of fiber failure under high power conditions while enabling increased power output through more efficient pump light coupling and higher permissible pump fiber counts.
4Ease of manufacture
If conventional combiner architecture is used, then manufacturing is straightforward, but pump efficiency is reduced and signal loss increases
Solution Approach 1:
The invention removes glass cladding from pump fibers only at the input coupling interface, a modification that can be integrated into existing fiber preparation processes. This targeted extraction improves pump efficiency and reduces signal loss by enabling direct pump light coupling, while the rest of the combiner structure remains compatible with standard manufacturing techniques.
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 enhances the power output and efficiency of optical fiber-based gain systems by allowing for increased pump energy introduction and reduced signal loss, improving manufacturing flexibility and reducing the risk of fiber failure.
Implementation Method 1
allows for coupling of partitioned high numerical aperture (NA) pump light outside a lasing cavity
Implementation Method 2
novel non-tapered high NA pump and signal combiner architecture that allows for the coupling of partitioned high NA pump light
Data Source
AI summary
As kilowatt class fiber laser and amplifier systems become more in demand, there are ongoing efforts to improve optical fiber laser and amplifier designs to maximize efficiency and further increase the capacity of these high-energy optical fiber lasers and amplifiers. The present disclosure provides a fiber laser or amplifier system configured to efficiently and conveniently generate and couple high numerical aperture and high-energy pump light into a fiber laser or amplifier system.