Mode Scrambler for Laser Light Source Angular Homogeneity
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Solution Overview
Problem
Laser-operated light sources often suffer from insufficient angular homogeneity, which negatively impacts the quality of light delivered to downstream processes like spectroscopy and surface inspection, leading to inhomogeneous light distribution and reduced optical quality.
Innovation Solution
The implementation of mode scramblers, specifically configured to bend optical fibers to different bend radii, improves the angular homogeneity of light by inducing mode mixing and uniformity across a range of angles, using either winding devices or clamping devices to create alternating curvatures, and employing additional optical fibers with larger diameters for enhanced homogenization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional optical fiber coupling is used to transfer light from the laser-operated light source, then the light transfer is simple and direct, but the angular homogeneity of the light is insufficient and inhomogeneous light distribution occurs
Solution Approach 1:
The patent introduces mode scramblers as intermediary devices between the optical fiber and the light delivery system. These mode scramblers mix the optical modes within the fiber to transform the angular distribution of light, thereby improving angular homogeneity without requiring fundamental changes to the light source or coupling mechanism.
Solution Approach 2:
The patent employs mode scramblers that dynamically change the optical parameters (mode distribution, angular distribution) of the light within the fiber. By actively manipulating these parameters through controlled fiber bending or mechanical elements, the system achieves improved angular homogeneity while maintaining a relatively simple overall structure.
2Illumination intensity
If mode scramblers are introduced to improve angular homogeneity, then light distribution uniformity improves, but device complexity increases
Solution Approach 1:
The patent divides the light delivery function into separate components: the optical fiber for light transfer and the mode scrambler for homogenization. This segmentation allows each component to be optimized independently, with the mode scrambler being a relatively simple add-on device that can be implemented through basic mechanical elements like bending fixtures or clamping mechanisms.
Solution Approach 2:
The mode scramblers described in the patent can be implemented using simple, low-cost mechanical elements such as bending fixtures, clamping devices, or even temporary fiber manipulations. These elements do not require complex active control systems or expensive components, making them cost-effective solutions for improving light homogeneity.
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 significantly enhances the angular and surface homogeneity of light, reducing negative impacts on measuring processes and improving the optical quality, particularly in the semiconductor industry, while using cost-effective and simple components.
Implementation Method 1
at least one mode scrambler assigned to the optical fiber and the optical fibers
Implementation Method 2
a laser for inputting laser energy into the plasma such that, under the impact of the laser radiation, the plasma generates useful light
Implementation Method 3
the plasma, in response to being irradiated with laser radiation, can emit radiation
Implementation Method 4
an ignition source for ionizing the gas in the chamber for generating a plasma
Implementation Method 5
the ignition source can be formed by means of an electrode pair
Data Source
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AI summary
A laser-driven light source encompasses a chamber for accommodating an ionizable gas and an ignition source for ionizing the gas in the chamber for generating a plasma. The light source furthermore encompasses a laser for inputting laser energy into the plasma such that, under the impact of the laser radiation, the plasma emits useful light, which forms the output signal of the light source, wherein provision is made for means for coupling the useful light into a transferring optical fiber. In the case of the light source according to the invention, at least one mode scrambler is assigned to the optical fiber or the optical fibers.