Wafer-scale inverted gallium phosphide-on-insulator rib waveguides for nonlinear photonics
Weiren Cheng, Zhaoting Geng, Zhuoyu Yu, Yihan Liu, Yatao Yang, Pengzhuo Wu, Houling Ji, Xiaolun Yu, Yifan Wang, Changjing Bao, Yi Li, Qiancheng Zhao
Abstract
We report a gallium phosphide-on-insulator (GaP-OI) photonic platform fabricated by an intermediate-layer bonding process aiming to increase the manufacture scalability in a low-cost manner. This is enabled by the “etch-n-transfer” sequence, which results in inverted rib waveguide structures. The shallow-etched 1.8 µm-wide waveguide has a propagation loss of 23.5 dB/cm at 1550 nm wavelength. Supercontinuum generation based on the self-phase modulation effect is observed when the waveguides are pumped by femtosecond pulses. The nonlinear refractive index of GaP, n 2 , is extracted to be 1.9 × 10 −17 m 2 /W, demonstrating the great promise of the GaP-OI platform in third-order nonlinear applications.