Laser Focusability Calculator

For a collimated beam, the diffraction-limited focal spot size of a laser beam depends on its wavelength, the size of the beam at the lens and its M2 value. Use this simple calculator to determine your laser's diffraction-limited focal spot size, assuming an ideal lens without aberrations and a collimated laser beam. If the beam is not collimated, then the full Laser Focal Spot Size Calculator should be used (set p to 0.01 and fill in λ, fl, θ, d).