Parameters
wx : half width of the incident beam waist in the XZ plane
wy : half width of the incident beam waist in the YZ plane
s : distance from the the primary principal plane to the waist of the incident elliptical beam
lam : wavelength
fi : effective focal length of the optical system
M2x : M square factor (M2) in the XZ plane
M2y : M square factor (M2) in the YZ plane
wix : half width of the emerging beam waist in the XZ plan
wiy : half width of the emerging beam waist in the YZ plane
six : distance from the secondary principal plane to the waist of the emerging beam in the XZ plane
siy : distance from the secondary principal plane to the waist of the emerging beam in the YZ plane
