Integrated all-optical manipulation of orbital angular momentum carrying modes via enhanced electro-optic Kerr effect

Abstract: Mode Division Multiplexing (MDM) technique using higher order Orbital Angular Momentum (OAM) carrying modes through a channelized bandwidth provides enhanced capacity communication systems. OAM based high-dimensional Quantum Key Distribution (QKD) encrypted channels also improve transmission rate and security. All-optical mode-selective spatial distribution manipulation is a significant function in implemented MDM and QKD networks. This paper proposes a novel versatile-designed integrated optical device with Y$_{cut}$ ridge Periodically Poled Lithium Niobate (PPLN) photonic wire configuration which acts as spatial mode converter for data modulated on higher order OAM$=\pm2\hbar$ modes. It is schemed in such a way that control the phase of decomposed guided modes by enhanced electro-optic Kerr effect via phase-mismatched cascaded polarization coupling interaction in PPLN sections. The low-loss, high-purity (91 %), and low-voltage proposed device enables to operate compatible with applicable commercial modulators in OAM based MDM and QKD communication systems.