Staircased Slow-Axis Collimators for WBC Pointing Error Compensation
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Solution Overview
Problem
High-power laser systems with wavelength beam combining (WBC) technology face pointing errors due to the tilt of dispersive elements, leading to beam smear and reduced efficiency in the non-WBC dimension.
Innovation Solution
The implementation of staircased slow-axis collimation (SAC) lenses, which vary in height and position, is used to compensate for pointing errors by manipulating individual interleaving mirrors, reducing beam smear and improving beam quality in the non-WBC dimension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the dispersive element is tilted in the non-WBC dimension to prevent first-order reflections from propagating back to the emitters, then the harmful reflections are eliminated, but pointing errors are introduced in the slow axis direction
Solution Approach 1:
Each slow-axis collimator is individually positioned at a specific height in the staircase arrangement, creating local variations in optical path length that compensate for the pointing errors introduced by the tilted dispersive element. This local adjustment of each collimator's position corrects the beam direction for that specific emitter while maintaining the overall system configuration.
Solution Approach 2:
The solution addresses the pointing error problem by introducing a vertical dimension (height variation) to the collimator arrangement. Instead of adjusting the tilted dispersive element or individual beam angles in the horizontal plane, the system uses vertical positioning of collimators in a staircase pattern to compensate for angular deviations, effectively solving a 2D pointing problem by adding a third dimension.
2Device complexity
If a single slow-axis collimation lens is used for all emitters to maintain system simplicity, then device complexity is reduced, but beam smear occurs in the non-WBC dimension due to pointing errors
Solution Approach 1:
The single collimation lens is segmented into multiple individual slow-axis collimators, each assigned to specific emitters. This segmentation allows each collimator to be independently positioned at different heights in the staircase arrangement, enabling precise correction of pointing errors for different emitters while maintaining manageable system complexity through modular design.
Solution Approach 2:
Each slow-axis collimator in the segmented arrangement is positioned at a locally optimized height specific to its associated emitter(s). This local quality adjustment ensures that each beam segment receives appropriate collimation at the correct vertical position, preventing beam smear while avoiding the need for a single complex adjustable lens system.
3Reliability
If the dispersive element is tilted at a non-zero angle to direct first-order reflections away from emitters, then system safety is improved, but beam smear is introduced at the dispersive element in the non-WBC dimension
Solution Approach 1:
The staircase positioning of slow-axis collimators is configured in advance to pre-compensate for the beam smear that will be introduced by the tilted dispersive element. By calculating and setting the appropriate vertical positions for each collimator before operation, the system proactively corrects the pointing errors and prevents beam smear from occurring, while maintaining the protective tilt of the dispersive element.
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 approach effectively reduces beam smear and enhances the efficiency of WBC systems by minimizing pointing errors, resulting in improved beam quality and stability, particularly in the slow-axis direction.
Implementation Method 1
Each collimator receives the one or more beams from a beam emitter and collimates the one or more beams in a non-WBC dimension
Implementation Method 2
a dispersive element that receives the beams and combines the beams in a wavelength-beam-combining (WBC) dimension into a multi-wavelength beam
Implementation Method 3
Each interleaving mirror reflects the one or more beams from a beam emitter toward the dispersive element
Data Source
AI summary
In various embodiments, pointing errors in a non-wavelength-beam-combining dimension of a laser system are at least partially alleviated via staircased collimation lenses.