Tunable polarization mode conversion using thin-film lithium niobate ridge waveguide

Lithium niobate on insulator (LNOI) waveguides, as an emerging technology, have proven to offer a promising platform for integrated optics, due to their strong optical confinement comparable to silicon on insulator (SOI) waveguides, while possessing the versatile properties of lithium niobate, such as high electro-optic coefficients. In this paper, we show that mode hybridization, a phenomenon widely found in vertically asymmetric waveguides, can be efficiently modulated in an LNOI ridge waveguide by electro-optic effect, leading to a polarization mode converter with 97% efficiency. Moreover, the proposed device does not require tapering or periodic poling, thereby greatly simplifying the fabrication process. It can also be actively switched by external fields. Such a platform facilitates technological progress of photonics circuits and sensors. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

LNOI waveguides, as an emerging technology, offer a promising platform for integrated optics with advantages such as modulating mode hybridization, high-efficiency polarization mode conversion, and active switching by external fields. Simplifying fabrication processes and facilitating technological progress in photonics circuits and sensors.