Complex sentence: Refractive modulators most often make use of electro-optic effect, other modulators are made with acousto-optic effect or magneto-optic effect or take advantage of polarization changes in liquid crystals.
Split into simpler sentences: Refractive modulators most often make use of the electro-optic effect. Some modulators utilize the acousto-optic effect or magneto-optic effect or take advantage of polarization changes in liquid crystals.