Laser Light Radiation Device Phase Pattern Alignment
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Solution Overview
Problem
In laser light irradiation devices, a mismatch between the center position of the image transferred to the entrance pupil plane and the center position of the entrance pupil plane can lead to a shift in the beam intensity center, resulting in deteriorated machining quality.
Innovation Solution
A laser light irradiation device that includes a spatial light modulator, an objective lens, an image-transfer optical system, a camera, and a controller to capture images of reflected light and adjust the phase patterns displayed on the modulator to determine and adjust for shifts between the image and entrance pupil plane centers, ensuring accurate condensing positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an image-transfer optical system transfers an image of laser light from the spatial light modulator to the entrance pupil plane of the objective lens, then the laser light can be condensed on the object, but the center position of the transferred image may not match the center position of the entrance pupil plane, causing a shift in beam intensity center and deteriorating machining quality
Solution Approach 1:
The patent employs a feedback mechanism where the camera captures the position of the laser light spot on the object, and this position information is fed back to the controller. The controller then adjusts the phase pattern displayed on the spatial light modulator to correct the position of the laser light spot, thereby aligning the beam intensity center with the desired position and improving machining quality.
Solution Approach 2:
The system performs self-alignment by automatically detecting the position of the laser light spot using the camera and autonomously adjusting the phase pattern through the controller. This self-service mechanism eliminates the need for manual alignment and ensures continuous positioning accuracy, resolving the contradiction between maintaining machining quality and achieving precise position alignment.
2Device complexity
If the center position of the transferred image and the center position of the entrance pupil plane do not match, then the system structure remains simple, but the beam intensity center shifts and machining quality deteriorates
Solution Approach 1:
The feedback mechanism using camera-based position detection and controller-driven phase pattern adjustment allows the system to maintain simple structure while achieving precise beam positioning. The feedback loop automatically compensates for misalignment without requiring complex mechanical adjustment mechanisms, thus preserving structural simplicity while improving machining quality.
Solution Approach 2:
The system changes the phase pattern parameters displayed on the spatial light modulator to adjust the beam position. By modifying the phase distribution parameters rather than physically realigning optical components, the system maintains structural simplicity while achieving precise control over beam intensity center positioning, thereby improving machining quality.
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 can automatically determine and adjust for image-transfer position shifts, improving the machining quality by ensuring precise alignment and reducing errors in the laser light condensing process.
Implementation Method 1
a spatial light modulator (SLM) 410, a liquid crystal layer 216 of which serves as a display unit, modulates the laser light L in accordance with a phase pattern displayed on the liquid crystal layer 216
Implementation Method 2
an objective lens 432 condenses the laser light L on the object 1
Implementation Method 3
a camera 473 to capture an image including a point image of reflected light of the laser light L irradiated on the object 1 and reflected on the reflection surface 1a
Data Source
AI summary
A laser machining device includes a laser light source, a spatial light modulator which includes a display unit, an objective lens, an image-transfer optical system, a camera and a controller. The controller executes first display processing and second display processing. According to first display processing, when the camera captures the image, the display unit displays a first phase pattern for adjusting a condensing position of laser light condensed by the objective lens to a first condensing position. According to second display processing, when the camera captures the image, the display unit displays a second phase pattern for adjusting the condensing position of the laser light condensed by the objective lens to a second condensing position different from the first condensing position in an irradiation direction of the laser light.