Galvanometer Scanning: How Fractional Lasers Draw Precise Patterns

A galvanometer scanner uses two fast-steering mirrors controlling X and Y, sweeping a single beam point-by-point across patterns — the square/circular scans of fractional CO2 and pattern coverage of non-ablative fractionals all ride on it. Positional precision and repeatability far exceed handpiece gliding.

• Positioning accuracy and repeatability: decides microbeam spacing uniformity — directly fluence uniformity.
• Scan speed: coverage rate and heat-accumulation rhythm.
• Pattern algorithms: randomized starts (avoiding double-heating), edge overlap handling, zone transitions.
• Focal-plane calibration: off-axis incidence distorts spots at pattern edges; premium systems compensate.

1. Fire a full pattern on a test plate; inspect point spacing by eye.
2. Run the same pattern twice and compare overlay.
3. Compare spot size at center vs edges — evidence of focal compensation.

Include scanning quality in acceptance for fractional devices (e.g., LEIJEX fractional CO2).

Symptoms of a failing galvo?

Distorted patterns, dropped points, drifting repeatability — energy fine, distribution chaotic; treatment shows doubled and missed spots.

More patterns = more advanced?

Pattern count is a software feature; outcomes depend on spacing, energy and heat management together. A few well-designed patterns beat dozens of gimmicks.

• Fractional Photothermolysis
• CO2 Fractional
• Assembly Quality