Pulse overlap calculator
Calculate longitudinal and cross-track pulse overlap from repetition rate, scan speed, effective spot size and hatch spacing. Check for coverage gaps or excessive pulse accumulation before a material test.
- Longitudinal and cross-track overlap
- Pulse spacing and density
- Gap and accumulation warnings
- No registration required
Convert laser motion settings into pulse coverage
Use the effective spot dimensions at the workpiece, not the scan field width. The result updates immediately as you change frequency, speed or hatch spacing.
How pulse overlap is calculated
The calculator separates overlap along the scan path from overlap between adjacent raster lines.
speed ÷ repetition rateThe center-to-center distance between consecutive pulses along the direction of travel.
(1 - spacing ÷ spot X) × 100A negative result means the pulse centers are farther apart than the effective X spot diameter.
(1 - hatch ÷ spot Y) × 100Compares adjacent line spacing with the effective Y spot diameter.
pulses/mm ÷ hatch spacingA geometric pulse-count estimate per square millimeter before beam-profile weighting.
Frequency and speed control spacing, not pulse energy alone
Increasing repetition rate or reducing travel speed raises longitudinal overlap. Average power only adds energy context unless the laser changes frequency and pulse energy together.
Read overlap as a process starting point
The best overlap depends on beam profile, contaminant, substrate, pulse duration, required finish and thermal sensitivity.
Know which setting changes which result
Adjust one variable at a time so the cause of a cleaning or marking change remains clear.
Higher frequency reduces pulse spacing
At the same scan speed, more pulses are delivered per millimeter and longitudinal overlap rises.
- Check whether pulse energy falls as frequency rises
- Confirm the laser's permitted frequency range
- Watch for excess thermal accumulation
Faster scanning lowers overlap
At a fixed frequency, higher speed increases the distance between pulses and may create incomplete coverage.
- Use actual workpiece travel speed
- Include scanner acceleration near edges
- Check corner and turnaround behavior
Effective beam size defines coverage
A larger measured spot increases geometric overlap, while wider hatch spacing reduces cross-track overlap.
- Measure at the working focus position
- Do not use the full scan field dimension
- Consider Gaussian edge intensity
Use overlap together with surface evidence
These conditions help identify what to test next; they are not universal machine presets.
| Observed Condition | Likely Geometry | What To Review | Recommended Check |
|---|---|---|---|
| Uncleaned stripes along travel | Negative or very low longitudinal overlap | Frequency, scan speed and X spot size | Reduce speed or increase frequency in controlled steps |
| Lines visible across the raster | Low cross-track overlap | Hatch spacing and Y spot size | Reduce hatch spacing and compare uniformity |
| Darkening or substrate tint | High pulse accumulation | Both overlap axes, fluence and passes | Reduce accumulation and inspect base-material change |
| Good center, weak edges | Geometric overlap ignores beam-edge intensity | Beam profile, focus and effective spot definition | Use a measured process spot rather than nominal diameter |
| Different result at corners | Scanner speed changes during motion | Acceleration, delays and path strategy | Inspect corner settings and compare straight sections |
Measure the values that make the estimate useful
Reliable overlap calculations depend on workpiece-level values rather than catalog assumptions.
Confirm the effective spot
Use a beam measurement or controlled mark at the same focal position, lens and working distance used in production.
Use actual repetition rate
Check the selected recipe and machine output range. Some lasers change pulse energy or shape with frequency.
Verify travel speed
Use the commanded process speed and review acceleration zones where the scanner cannot maintain that value.
Confirm hatch definition
Measure center-to-center line spacing and note whether alternating, cross-hatch or rotated passes are used.
Turn the calculation into a controlled material test
Send your material, contaminant, required finish and current settings. Oceanplayer can compare overlap, fluence and cleaning result before machine selection.
Share the application
Material, coating, dimensions, target finish and production speed.
Compare settings
Test frequency, speed, spot, hatch spacing, fluence and passes.
Review evidence
Evaluate surface photos, video, timing and recommended configuration.
Continue your laser process planning
Use overlap together with energy, machine power and production-rate calculations.
Pulse overlap calculator questions
Practical answers for pulsed laser cleaning, marking and surface-processing trials.