beam waist
3.By measuring M~2 factor and the waist of output beam with CCD beam analyzer,the beam waist of the TEM_(00) mode can be deduced according to the law of multi-mode Gaussian beam propagation. Based on the ABCD matrix theory of stable resonator,the thermal focal length of the active medium is easily obtained.
8.When the beam waist wy of blue-detuned SEGB along the y direction is 10 mm, and its wx is decreased from 10 mm to 1mm, the absolute diffracted intensity from the SEGB surface will be 10 times of that from the SGB surface, which can be used to reflect an incident atomic beam with a higher normal velocity.

