Laser Brightness Calculator

Laser Brightness (Radiance)

Laser brightness, also called radiance, measures how much optical power passes through a unit area within a unit solid angle. It is essential for laser safety classification, beam quality comparison, and optical system design.

Formula

For small divergence angles, the solid angle is approximated as \(\Omega = \pi \left(\frac{\theta}{2}\right)^2\), where \(\theta\) is the full beam divergence angle in radians, \(P\) is laser power, and \(A\) is the beam cross-sectional area.

Practical Notes

Divergence is often specified in milliradians (mrad). Beam diameter is typically given at the 1/e² intensity points for Gaussian beams. Higher radiance means a more concentrated, brighter beam.