Abstract
Integrated photonic chips offer a breakthrough solution for the miniaturization and cost reduction of interferometric fiber optic gyroscope (IFOG). In this work, we propose an integrated optical transceiver module based on a cascaded bent waveguide-based polarization-control silicon nitride (Si₃N₄) chip. The module incorporates a polarizer, beam splitter, superluminescent diode (SLD), and photodetector within a millimeter-scale footprint through hybrid integration. The Si₃N₄ chip measures only 5 mm × 2.5 mm and achieves a polarization extinction ratio (PER) of 28 dB, with an output power of 126 μW per channel. Furthermore, an ultra-high-aspect-ratio Si₃N₄ waveguide structure is designed and fabricated to form an on-chip interferometric waveguide ring with a length of 3.0 m and a diameter of 30 mm. The overall insertion loss of the ring is 14.0 dB, with a PER of 25 dB. The interferometric optical gyroscope system constructed using these components demonstrates a bias instability of 2.5 °/h (Allan). The collaborative innovation between Si₃N₄ optical transceiver module and Si₃N₄ waveguide ring demonstrates the feasibility of chip-scale miniaturization and cost reduction for all key components of IFOG using integrated photonic and optoelectronic technologies, thereby advancing the development of fully chip-integrated IFOG systems.