Control of spin angular momentum in quasi-phase-matched material.
A method to control spin angular momentum (SAM), based on mutual effects of a electro-optic effect and a quasi-phase-matched (QPM) technique in QPM material, is proposed. By controlling the external electric field or operating wavelength, the transfer between left- and right-handed circularly polarized photons is achieved, thus the total SAM is manipulated. The external electric field needed in this method for the complete modulation of the total SAM per photon from 0 to ħ is as low as 0.44 kV/cm. This method will see its applications in micromanipulation by light.