Space compatibility of emerging, wide-bandgap, ultralow-loss integrated photonics

Integrated photonics has revolutionized optical communication, sensing, and computation, offering miniaturized and lightweight solutions for spacecraft with limited size and payload. Novel chip-scale instruments based on ultralow-loss integrated photonic platforms, including lasers, frequency combs and atomic traps, have been developed for space applications. Therefore, quantifying the space compatibility of ultralow-loss photonic integrated circuits (PICs), particularly their radiation resistance, is critical. This study experimentally evaluates the radiation resistance of ultralow-loss Si₃N₄, 4H-SiC, and LiNbO₃ PICs under intense γ-ray and high-energy proton irradiation. Results show that proton irradiation with 1.1 × 10¹⁰ p/cm² total flux does not significantly increase optical loss or alter the refractive index of these PICs, while γ-ray irradiation with 1.2 Mrad accumulated dose only marginally increases their optical loss. These findings provide preliminary evidence of the excellent space compatibility of ultralow-loss Si₃N₄, 4H-SiC, and LiNbO₃ PICs, highlighting their potential for compact and lightweight space systems.