Spot Size

The spot size of a beam is the beam diameter in free space. It varies along the length of the beam according to the equation:

𝜔𝑧.= 𝜔0.,-1+,,,𝑧-,𝑧-𝑟...-2..



And ω0 is the beam diameter at r=0, which is the minimum beam experienced by the beam.

Spot Size

Related Terms: Acceptance Angle, Core, Mode Field Diameter (MFD), Numerical Aperture (NA)