Multi-Axis Acousto-Optic Deflection for Precise Laser Energy Control
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Solution Overview
Problem
Current multi-axis acousto-optic deflector (AOD) systems in laser-processing systems face challenges in efficiently directing laser energy across two-dimensional scan fields without causing undue damage to workpieces, requiring separate laser systems for different types of workpieces due to varying power requirements.
Innovation Solution
A multi-axis AOD system comprising a first AOD and a second AOD, both driven by RF drive signals to maintain at least substantially the same diffraction efficiency, allowing for the generation of highly-attenuated first-order beams that can be controlled for precise energy distribution across a two-dimensional scan field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multi-axis AOD systems are used to direct laser energy across two-dimensional scan fields, then beam positioning capability is improved, but the risk of damaging workpieces increases due to difficulty in controlling laser energy distribution
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the diffraction efficiency of each AOD based on its specific characteristics (e.g., bandwidth, diffraction efficiency at different frequencies). The controller modifies operating parameters such as RF drive signal frequencies and amplitudes to optimize energy distribution, ensuring that the combined diffraction efficiency produces the desired beam intensity without exceeding workpiece damage thresholds.
2Manufacturing precision
If separate laser systems are used for different workpiece types, then processing precision for specific workpieces is improved, but system complexity and cost increase
Solution Approach 1:
The patent implements universality by designing a single multi-axis AOD system that can process different workpiece types through dynamic parameter adjustment. The controller enables each AOD to be independently configured with optimal diffraction efficiency settings for various workpiece characteristics, allowing one system to replace multiple specialized laser systems while maintaining processing precision across different material types and thicknesses.
3Adaptability or versatility
If AODs are driven at different diffraction efficiencies, then adaptability to different workpiece characteristics is improved, but energy distribution control precision deteriorates
Solution Approach 1:
The patent applies feedback by implementing a controller that monitors and adjusts the diffraction efficiency of each AOD based on the desired output beam characteristics and workpiece requirements. The controller receives input parameters (workpiece type, thickness, material properties) and dynamically calculates optimal drive signal parameters for each AOD, ensuring that the combined energy distribution achieves precise control while maintaining adaptability to different workpiece characteristics.
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
Enables efficient and controlled material processing across different workpiece types without damaging them, by ensuring the diffraction efficiency is optimized for the specific workpiece thickness, allowing for versatile laser processing capabilities within a single system.
Implementation Method 1
The transducer 104 is generally a piezoelectric transducer, and is operative to vibrate in response to an externally-applied RF signal
Implementation Method 2
The acoustic wave is manifested within the AO cell 102 as periodic series of regions of expansion and compression, thereby creating a periodically changing refractive index within the AO cell 102. The periodically changing refractive index functions like an optical grating that can diffract a beam of laser light
Implementation Method 3
Diffracting the incident beam of laser light produces a diffraction pattern that typically includes zeroth- and first-order diffraction peaks, and may also include higher-order diffraction peaks
Data Source
AI summary
An apparatus includes an acousto-optical deflector (AOD) system operative to deflect a beam of laser energy within a two-dimensional scan field. The AOD system includes a first AOD operative to deflect the beam of laser energy along a first axis of the two-dimensional scan field; a second AOD arranged optically downstream of the first AOD, wherein the second AOD is operative to deflect the beam of laser energy along a second axis of the two-dimensional scan field; and a controller operatively coupled to the AOD system. The controller is configured to drive each of the first AOD and the second AOD to deflect the beam of laser energy within the two-dimensional scan field and is further configured to drive the first AOD and the second AOD at at least substantially the same diffraction efficiency.