Wavelength Beam Combining with Reduced Beam Spacing
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Solution Overview
Problem
Current wavelength beam combining technologies do not adequately increase the output and power density of laser beams, limiting their effectiveness in applications such as cutting, drilling, and marking materials.
Innovation Solution
A wavelength beam combining device that uses a combination of optical elements and diffraction gratings to reduce the distance between collimated beams with different peak wavelengths, allowing them to be efficiently combined and increased in power density, incorporating a beam reducer and polarization split and synthesis mechanisms to enhance output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional wavelength beam combining is used, then multiple laser beams can be combined, but the output and power density are insufficient
Solution Approach 1:
The patent transforms the beam arrangement from a one-dimensional linear array to a two-dimensional array configuration. Multiple collimated beams are arranged in both horizontal and vertical directions, allowing for more efficient spatial packing and higher power density consolidation in the focal region, thereby resolving the insufficient output and power density issue
Solution Approach 2:
The patent implements preliminary collimation of individual laser beams before they enter the combining optical system. Each beam is pre-collimated to ensure uniform wavefronts and optimal coupling into the combining optics, which maximizes the energy transfer efficiency and final output power of the combined beam
2Power
If beam distance is reduced using optical elements, then power density increases, but beam quality may deteriorate
Solution Approach 1:
The patent introduces a telecentric lens system as an intermediary optical element between the beam arranging stage and the diffraction grating. This telecentric lens maintains beam parallelism and uniform spacing while reducing the overall beam array distance, thereby achieving high power density without compromising beam quality through controlled intermediary transformation
Solution Approach 2:
The patent carefully controls and adjusts key optical parameters including beam spacing, beam diameter, and convergence angle during the combining process. By optimizing these parameters, the system achieves maximum power density while maintaining beam quality metrics such as M² factor and focal spot uniformity
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
The solution significantly increases the output and power density of combined laser beams, enabling higher performance in material processing applications like cutting, drilling, and welding with improved beam quality and energy conversion efficiency.
Implementation Method 1
a first diffraction grating and a second diffraction grating. The first diffraction grating is disposed at a position where the plurality of collimated beams exiting from the optical element are received and is configured to diffract the plurality of collimated beams in different directions depending on wavelengths
Implementation Method 2
an optical element configured to reduce a distance between beam central axes of the plurality of collimated beams
Data Source
AI summary
A wavelength beam combining device configured to combine collimated beams of different peak wavelengths whose central axes emitted in a first direction are arranged in a second direction intersecting the first direction, includes: an optical element configured to reduce a distance between beam central axes of the collimated beams and to cause the collimated beams with the reduced distance therebetween to exit; and first and second diffraction gratings. The first diffraction grating is disposed at a position where the collimated beams exiting from the optical element are received and to diffract the collimated beams in different directions depending on wavelengths to allow the collimated beams to enter the second diffraction grating. The second diffraction grating is configured to further diffract the collimated beams diffracted by the first diffraction grating to form a wavelength-combined beam and is configured to cause the wavelength-combined beam to exit.