Linear polarization rotation tilt is a form of polarization aberration
present in polarizing beamsplitter cubes when they are used in imagin
g systems. It is caused by the rotation of the polarizing axis (define
d by the plane of incidence at the beamsplitting interface) for off-ax
is angles of incidence. This aberration is inherent to the geometry of
the cube and is unavoidable, causing beam-routing errors and undesira
ble losses. In systems that use two or more polarizing beamsplitter cu
bes in succession, the cubes can be oriented to either minimize or max
imize the loss, where the maximum loss is five times the minimum loss.
This polarization aberration is described and a way to minimize beam-
routing errors associated with this aberration in a 4-F optical system
is demonstrated.