An active straight waveguide polarization rotator in single crystal thin film barium titanate-on-insulator

• DOI: 10.1063/5.0130516
• Publication Date: 2023-01-19T11:24:06Z
• Authors: Yu Cao; Jun Da Ng; Hong-Lin Lin; Siew Li Tan; Aaron Danner
• Keywords: Extinction ratio; Barium titanate; Pockels effect; Waveguide

Electro-optic materials play an essential role in telecommunications. In active devices like Mach–Zehnder modulators, typically the diagonal Pockels coefficients are employed to induce optical phase shift through electrical tuning of refractive index along optic axis. On other hand, waveguide polarization rotators usually passive where asymmetric structures or specially designed couplers used. this Letter, we exploit off demonstrate straight rotator using a c-axis single crystal thin film barium titanate (BTO)-on-insulator, with maximum power conversion ∼30% from input TE (or TM) mode into its orthogonal observed. The device is switched on applied voltage and demonstrated simple waveguide. A TM output extinction ratio 26.1 dB achieved input. r51 value BTO estimated be around 600 pm/V. This work adds different rotation scheme photonics family.