Parameters
wo : waist radius of the incident embedded gaussian beam
z : distance from the first lens to the waist of the incident embedded gaussian beam
lam : wavelength
fi1 : effective focal length of the first lens
fi2 : effective focal length of the second lens
L : distance between the two lenses
M2 : M-square factor
wio : waist radius of the emerging embedded gaussian beam
zi : distance from the second lens to the waist of the emerging embedded gaussian beam
