# Wavefront curvature ## Gaussian beam The wave front curvature for a [Gaussian beam](Gaussian%20beam.md) is expressed as $R(z)=z\bigg[1+\bigg(\frac{z_R}{z}\bigg)\bigg].$ ^a4342b  (Image adapted from Siegman A. _Lasers_) #Electromagnetism/Optics/waveOptics/GaussianBeamOptics #Electromagnetism/Optics/waveOptics