Gaussian beam divergence calculator
Unitless
Half-Angle Divergence (θ)
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mrad
Full-Angle Divergence (2θ)
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mrad
How it works?
Laser beams are not perfectly parallel; they expand as they propagate through space. This rate of expansion is called Beam Divergence. It is governed by diffraction limits and is inversely proportional to the beam waist size (a smaller starting beam spreads out faster).
$$ \theta = \frac{M^2 \lambda}{\pi w_0} $$
Half-Angle Formula (Radians)
Where:
- \(\theta\) : Half-angle divergence (in Radians).
- \(\lambda\) : Wavelength of the laser.
- \(w_0\) : Beam Waist Radius (at the narrowest point).
- \(M^2\) : Beam Quality Factor (1.0 = Ideal Gaussian).
Note: Commercial lasers often specify "Full Angle" divergence (\(2\theta\)). This calculator provides both values converted to Milliradians (mrad) for convenience.