Controlling the polarization state of light at a fast speed is important in both classical and quantum regimes. Here, we present an easily integrated compact tunable linear polarization-state generator of single photons in the telecom wavelength band on a periodically poled lithium niobate on insulator (PPLNOI) chip. The linear polarization of single photons can be continuously rotated by applying a transverse electric field utilizing the electro-optic (EO) effect. With strong light confinement and the large EO coefficient in the PPLNOI ridge waveguide, dramatically reduced driving voltage and fast-speed modulation is realized. Moreover, quantum entanglement is well maintained during the switching of polarization states, as proved in the time-energy entanglement measurement. The scheme holds promise for realizing integrated quantum optics.

• Received 10 March 2020
• Revised 4 May 2020
• Accepted 26 May 2020

DOI:https://doi.org/10.1103/PhysRevApplied.13.064068