We're going to add a Newfocus 4064 phase modulator (EOM) to the beam path to allow us to set up a PDH lock. We plan to place the phase modulator at the waist position of the beam. The waist size is 100um and the EOM has a 2mm diameter so we should have plenty of clearance. The EOM has a maximum intensity of 20 W/mm^2, and our beam has 60mW of power with a 100um waist giving a peak intensity of 4 W/mm^2, safely below the EOM's damage threshold.