# Laser beam diameters: What are the units of 1/e^2?

I own an argon ion laser head with a beam diameter of '0.70' (using $1/e^2$ width).

What is the unit on the 0.70? And can it be converted to something more intuitive, such as meters?

The $1/e^2$ refers to the way that the size of the beam diameter is defined. More information about this and the most common alternative measure of FWHM (full width at half maximum intensity) can be found here.