Laser Power Density Calculator

Peak Power Density
--- W/cm²
Equivalent in kW/cm²
--- kW/cm²

How it works?

Understanding Peak Intensity

Most laser beams follow a Gaussian ($TEM_{00}$) intensity profile, meaning the energy is concentrated in the center. The "Average" density assumes the energy is spread evenly, which underestimates the intensity at the center by 50%.

To predict laser damage thresholds or cutting speeds accurately, you must calculate the Peak Power Density or Fluence:

$$ I_{peak} = \frac{2 \cdot P}{\pi \cdot w^2} $$ Gaussian Beam (CW)
$$ F_{peak} = \frac{2 \cdot E}{\pi \cdot w^2} $$ Gaussian Beam (Pulsed)

Where:

  • I : Power Density (Irradiance) in \(W/cm^2\).
  • F : Fluence (Energy Density) in \(J/cm^2\).
  • P : Average Power (Watts).
  • E : Pulse Energy (Joules).
  • w : Beam Radius (half of the diameter).

Note: For a "Top Hat" (Flat Top) beam, the energy is uniform, so the factor of "2" is removed from the equation (\( I = P / \pi w^2 \)).