What are the advantages of PEMs over other forms of polarization modulation?

PEMs have several unique features such as wide spectral range, large aperture, wide acceptance angle, and high precision of phase modulation. The PEM is typically used for fast, high sensitivity measurements. Fused silica PEM optical elements are isotropic when no stress is applied (as contrasted with Pockels cells and electro-optic modulators). This gives the PEM a large acceptance angle.  Click here for more information.