Efficiency of electrooptic spin-to-orbital angular momentum conversion in crystals

• We introduce an electrooptic figure of merit for the photon CAM-to-OAM conversion.
• The effective EO coefficients for the SAM-to-OAM conversion are derived.
• Bi12TiO20 crystals reveal the highest figure of merit.
• The efficiency of the SAM-to-OAM conversion is measured experimentally.

We introduce a figure of merit for the photon spin-to-orbital angular momentum conversion via electrooptic (EO) Pockels effect in single crystals. Relations for the effective EO coefficients are derived for different symmetry groups. We show that Bi12TiO20 crystals reveal the highest figure of merit among well studied crystalline EO materials. The efficiency of the spin-to-orbital angular momentum conversion is measured experimentally for a number of single crystals.