Parameters
wo : waist radius of the incident gaussian beam
wf : mode radius of the fiber optic
T : transmission coefficient at the entrance of the fiber optic
lam : wavelength
dx : lateral shift of the gaussian beam along X axis
dy : lateral shift of the gaussian beam along Y axis
dz : defocus of the gaussian beam regarding the fiber entrance
tiltx : tilt of the gaussian beam around the X axis
tilty : tilt of the gaussian beam around the Y axis
C : coupling ratio
