Laser Beam Splitting with OCT Keyhole Depth Switching
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Solution Overview
Problem
Existing laser processing devices can only measure the depth of a single keyhole during simultaneous processing at multiple locations on a workpiece due to the limited availability of OCT light.
Innovation Solution
A laser processing device that branches laser light into multiple beams and uses a separate optical interferometer with measurement light of a different wavelength to generate optical interference signals for each processing point, allowing for the measurement of keyhole depths at multiple locations by controlling the position of mirrors to direct measurement light to each point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single OCT light is used to measure keyhole depth, then the measurement system remains simple, but only one keyhole depth can be measured at a time even when multiple laser beams process multiple locations simultaneously
Solution Approach 1:
The single OCT light source is designed to serve multiple processing points by using a movable mirror that directs the measurement light to different locations. The measurement light sharing unit enables one OCT light to perform measurement functions at multiple keyholes sequentially, making the measurement system universal across multiple processing points without requiring separate OCT lights for each location.
Solution Approach 2:
A movable mirror is introduced to dynamically redirect the measurement light between different processing points. The mirror's position can be changed to direct measurement light to either the first or second processing point, enabling flexible and adaptive measurement capability across multiple locations while maintaining a single OCT light source.
2Measurement precision
If separate measurement systems are provided for each processing point, then all keyhole depths can be measured simultaneously, but the device complexity and cost increase significantly
Solution Approach 1:
Instead of providing separate OCT lights for each processing point, the invention makes a single OCT light universal by enabling it to measure multiple keyholes through the measurement light sharing unit. This approach maintains comprehensive measurement precision across all processing points while avoiding the complexity of multiple independent measurement systems.
3Productivity
If laser processing is performed at multiple locations simultaneously, then productivity increases, but the ability to measure all keyhole depths increases only if multiple OCT lights are used
Solution Approach 1:
The movable mirror dynamically adjusts the measurement light path to match the simultaneous processing locations. When lasers process multiple points simultaneously, the mirror can be positioned to direct measurement light to the corresponding processing points, ensuring that depth measurement coverage keeps pace with processing productivity without requiring multiple fixed OCT light sources.
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 the simultaneous measurement of keyhole depths at multiple processing points on a workpiece, improving the efficiency of laser processing operations.
Implementation Method 1
an optical interferometer that emits measurement light having a wavelength different from a wavelength of the laser light, and generates an optical interference signal based on the measurement light reflected by the processing point
Implementation Method 2
a lens that condenses the laser light and the measurement light
Data Source
AI summary
A laser processing device includes a first branching unit that branches laser light into first laser light emitted to a first processing point and second laser light emitted to a second processing point, an optical interferometer that emits measurement light having a wavelength different from a wavelength of the laser light, and generates an optical interference signal based on the measurement light, a lens that condenses the laser light and the measurement light, a first mirror that changes incident positions of the laser light and the measurement light on the lens, a second mirror that changes an incident position of the measurement light on the first mirror, a controller that controls an operation of the second mirror, and a measurement processing section that derives a depth of a keyhole based on the optical interference signal.