It would appear that with a quarter wave plate and a pockels cell one may convert the plane of polarisation of a linearly polarised coherent light beam to any other angle with a suitable voltage on the pockels cell. I use the term "convert" advisedly as I do not see this as rotation (as for example in a Farady Rotator).

I have read through some literature but am not familiar with polarisation ellipses and the articles have left me with no physical view of what happens, unlike the standard view of light beam switching with a pockels cell, with which I am very familiar.