Correcting Diode Laser Beam Astigmatism with Offset Scanners
diode lasercalibrationadvancedalignment
The Oval Beam Problem
Many high-power diode lasers (like 10W+ models) use beam combining optics, which can result in an astigmatic, rectangular focused spot rather than a perfect circle. This causes cutting to be faster in one axis (e.g., X) than the other (Y).
The Correction Process
1. Perform a cross-hair test: etch a precise cross (+) at speed. 2. Measure the line thickness in both axes. 3. In LightBurn, enable 'Scanning Offset Adjustment.' 4. Input the measured delay or offset (in ms) for the faster axis. This digitally aligns the start of the laser pulse across both axes, correcting the distortion and normalizing cut speeds.