Beam Divergence Calculator
Aperture dia. mm

Divergence is the angle the beam is expanding. It is usually in the units of milli-radians. (mrad)

Use this to determine the beam divergence given 2 beam diameter values at a given separation.

Distance m
Second dia. mm

Beam Diameter at Lens Calculator
Divergence mrad If you know your the aperture at the laser tube, the divergence and the length from the tube aperture to the lens, you can calculate the beam diameter at the lens.
Aperture mm
Distance m

Diameter at lens mm
Spot Size Calculator
Beam dia. (D) mm Spot Dia. = 1.27 * f * wavelength * M2/D

Calculate the focused spot size
M = 1 for a perfect gaussian TEM00 beam

From...parallax-tech.com FAQ

Wavelength mm
M2
Focal Length (f) mm

Focused spot size mm
Beam Power watt

Power Density w/mm2
Depth of field Calculator
Beam dia. mrad DOF = 2.5 * wavelength * (f/D)2

What is the length of the beam in the area where the beam is less than 140% of the spot size.

From...parallax-tech.com FAQ

Focal Length mm
Wavelength mm

Depth of field mm

Send comments, suggestions, corrections to bdring@buildlog.net