Fiber Laser Pump Control Using Selective LD Module Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In variable-output fiber lasers with multiple LD modules, changes in laser output power cause significant shifts in oscillation wavelength, leading to inefficient use of pumping light and increased manufacturing costs due to the use of wavelength stabilizing elements.
Innovation Solution
A control device that adjusts the number of LD modules supplied with driving current based on the set laser output power, using a digital potentiometer and control section to manage the resistance values of variable resistors, thereby reducing oscillation wavelength shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of LD modules supplied with driving current is reduced to control laser output power, then the oscillation wavelength shifts due to current variation, but adding wavelength stabilizing elements increases manufacturing cost and reduces yields
Solution Approach 1:
The patent changes the operating parameters of LD modules by adjusting the number of modules supplied with driving current based on the set laser output power value. When laser output power is reduced, fewer LD modules are supplied with current, which simplifies the control mechanism while managing wavelength shifts through parameter adjustment rather than adding stabilizing elements
Solution Approach 2:
The patent segments the LD module group into multiple individual modules that can be independently controlled. By selectively supplying driving current to specific numbers of modules based on required output power, the system achieves flexible power control without requiring wavelength stabilizing elements in each module, thereby reducing manufacturing cost and improving yields
2Loss of energy
If a narrow-bandwidth oscillation wavelength is used to improve pumping light efficiency, then the oscillation wavelength must be stabilized, but stabilizing the wavelength in variable-output lasers requires additional components that increase cost and complexity
Solution Approach 1:
The patent maintains narrow-bandwidth oscillation characteristics by controlling the number of active LD modules rather than using complex stabilization mechanisms. This parameter-based control approach preserves pumping light efficiency while avoiding the need for additional wavelength stabilizing elements that would increase device complexity
Solution Approach 2:
The patent extracts the wavelength stabilization function from the individual LD modules by using a centralized control approach that manages the number of active modules. This eliminates the need for wavelength stabilizing elements within each module, reducing device complexity while maintaining pumping light efficiency through controlled narrow-bandwidth operation
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
Efficiently uses pumping light by minimizing oscillation wavelength shifts, reducing residual light, and minimizing optical component deterioration while maintaining high power efficiency.
Implementation Method 1
at least two laser diode (LD) modules 211, 212 each supplying pumping light 31b to a variable-output fiber laser 3
Implementation Method 2
a rare earth element such as Yb, which is a dopant of an optical fiber, is pumped by using a laser beam (hereinafter, referred to as 'pumping light') outputted from an LD module. The fiber laser thus achieves laser beam recursive amplification
Data Source
AI summary
A control device for controlling two or more laser diode (LD) modules each supplying pumping light to a variable-output fiber laser, includes: a controller that sets, in accordance with a set value of laser output power of the variable-output fiber laser, a number of LD modules to which a driving current is supplied among the two or more LD modules.