  We present performance studies of a segmented optical module for the
IceCube-Gen2 detector. Based on the experience gained in sensor development for
the IceCube Upgrade, the new sensor will consist of up to eighteen 4 inch PMTs
housed in a transparent pressure vessel, providing homogeneous angular
coverage. The use of custom molded optical `gel pads' around the PMTs enhances
the photon capture rate via total internal reflection at the gel-air interface.
This contribution presents simulation studies of various sensor, PMT, and gel
pad geometries aimed at optimizing the sensitivity of the optical module in the
face of confined space and harsh environmental conditions at the South Pole.
