iPhone app for calculating laser beam spot sizes
ULO Optics has released a free iPhone app for calculating spot sizes. The Spot Calculator calculates laser beam spot size and Rayleigh length (depth-of-focus) for a given beam, taking into account beam quality, wavelength, beam diameter, and focus length. The newest version (2.0) includes a calculator for minimum thickness of cutting lenses so they withstand cutting gas pressure in the nozzle.
One version of the app is optimized for Gaussian beams (mostly CO2); another calculates focus diameter and power density for fiber-delivered lasers. Input values are the laser power, fiber diameter, and collimating and focusing optics -- based on the fiber NA, the collimated beam diameter and depth-of-focus will be calculated.