Diffractive Optical Element for Laser Beam Combining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser beam combining devices fail to effectively enhance the irradiation power density of combined laser beams due to mismatched focal positions and varying diffraction angles of circular laser beams with different wavelengths.
Innovation Solution
A laser beam combining device incorporating a diffractive optical element that diffracts circular laser beams based on their wavelengths, ensuring equal local diffraction angles and improved focal alignment, combined with a magnifying and condensing optical system to enhance irradiation power density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional laser beam combining devices are used to combine multiple circular laser beams, then the laser beams can be combined, but the irradiation power density of the combined beam is insufficient due to mismatched focal positions and varying diffraction angles
Solution Approach 1:
The diffractive optical element introduces local quality variations through wavelength-dependent diffraction. Each wavelength component of the circular laser beams experiences tailored diffraction angles that compensate for their different propagation characteristics, enabling all wavelengths to converge at the same focal position despite their inherent differences in outer diameter dimensions per unit propagation distance
Solution Approach 2:
The invention changes the diffraction angle parameter as a function of wavelength. By designing the diffractive optical element with specific groove patterns, the local diffraction angles are adjusted for different wavelengths incident at different angles, transforming the problematic wavelength-dependent behavior into a corrective mechanism that achieves uniform focal positioning
2Productivity
If circular laser beams with different wavelengths are combined using conventional methods, then beam combining is achieved, but the diffraction angles vary causing poor light condensing performance
Solution Approach 1:
The diffractive optical element serves as an intermediary component between the emission optical system and the condensing optical system. It mediates the wavelength-dependent propagation differences by introducing controlled diffraction that compensates for the varying outer diameter dimensions, enabling all laser beams to be properly conditioned for high-efficiency condensing without requiring complex individual beam control mechanisms
3Illumination intensity
If the diffractive optical element is designed to match focal positions, then irradiation power density is enhanced, but the device structure becomes more complex
Solution Approach 1:
The diffractive optical element merges multiple functions into a single component: it simultaneously controls diffraction angles for different wavelengths, compensates for varying propagation characteristics, and ensures focal position alignment. This consolidation achieves the desired irradiation power density enhancement without requiring separate adjustment mechanisms for each parameter, thereby limiting the increase in overall device complexity
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 device achieves a significant increase in irradiation power density of the synthetic laser beam by matching diffraction angles and focal positions, resulting in improved light condensing performance and intensity compared to conventional systems.
Implementation Method 1
a diffractive optical element that is concentric and diffracts the plurality of circular laser beams, in which the diffractive optical element diffracts the plurality of circular laser beams in accordance with the wavelengths of the circular laser beams
Data Source
AI summary
A laser beam combining device includes an emission optical system that emits a plurality of circular laser beams propagated coaxially and having mutually different wavelengths, and a diffractive optical element that is concentric and diffracts the plurality of circular laser beams. The diffractive optical element diffracts the plurality of circular laser beams in accordance with the wavelengths of the circular laser beams, such that local diffraction angles of diffracted light of the plurality of circular laser beams incident at mutually different local incidence angles are equal to each other.