On-chip reconfigurable polarization splitter-rotator fabricated on a thin-film lithium niobate photonic integrated circuit platform

We report the conception and experimental demonstration of a tunable polarization splitter-rotator (PSR) integrated into a thin-film lithium niobate (TFLN) photonic platform based on a 45° PSR. The device operates over the C-band and leverages the thermo-optical tunability of TFLN to achieve precise and stable manipulation of the polarization in a millimeter scale footprint. The PSR exhibits a polarization extinction ratio of 23.3 dB on average near 1550 nm, enabling separation of both polarization channels. This performance highlights the potential of TFLN for dual-polarization applications in optical communications, sensing, and beyond.