  This paper is the second in a set of two investigating tilt-to-length (TTL)
coupling. TTL describes the cross-coupling of angular or translational jitter
into an interferometric phase signal and is an important noise source in
precision interferometers, including space gravitational wave detectors like
LISA. We discussed in 10.1088/2040-8986/ac675e the TTL coupling effects
originating from optical path length changes, i.e. geometric TTL coupling.
Within this work, we focus on the wavefront and detector geometry dependent TTL
coupling, called non-geometric TTL coupling, in the case of two interfering
fundamental Gaussian beams. We characterise the coupling originating from the
properties of the interfering beams, i.e. their absolute and relative angle at
the detector, their relative offset and the individual beam parameters.
Furthermore, we discuss the dependency of the TTL coupling on the geometry of
the detecting photodiode. Wherever possible, we provide analytical expressions
for the expected TTL coupling effects. We investigate the non-geometric
coupling effects originating from beam walk due to the angular or translational
jitter of a mirror or a receiving system. These effects are directly compared
with the corresponding detected optical path length changes in
10.1088/2040-8986/ac675e. Both together provide the total interferometric
readout. We discuss in which cases the geometric and non-geometric TTL effects
cancel one-another. Additionally, we list linear TTL contributions that can be
used to counteract other TTL effects. Altogether, our results provide key
knowledge to minimise the total TTL coupling noise in experiments by design or
realignment.
