  In this work, we study the effect of beam deviation angle at the reception
side and calculate the theoretical demultiplexed collected energy for up to 15
modes, investigating the influence of the ratio between incoming beam size and
fundamental HG mode's waist. We show this approach greatly enhances the
collection efficiency, tolerating tip-tilt error of more than 3 times compared
to a Gaussian beam alone. We also show that, depending on wait size, a
trade-off between collection efficiency at small angles and maximum acceptance
angle can be achieved.
