Silicon nitride (SiNx${\mathrm{SiN}}_x$) is an appealing waveguide material choice for large-scale, high-performance photonic integrated circuits (PICs) due to its low optical loss. However, SiNx${\mathrm{SiN}}_x$ PICs require high electric power to realize optical reconfiguration via the weak thermo-optic effect, which limits their scalability in terms of device density and chip power dissipation. We report a 6-mode programmable interferometer PIC operating at the wavelength of 1550 nm on a CMOS-compatible low-temperature inductance coupled plasma chemical vapor deposition (ICP-CVD) silicon nitride platform. By employing suspended thermo-optic phase shifters, the PIC achieves 2×$2\times$ improvement in compactness and 10×$10\times$ enhancement in power efficiency compared to conventional devices. Reconfigurable 6-dimensional linear transformations are demonstrated including cyclic transformations and arbitrary unitary matrices. This work demonstrates the feasibility of fabricating power-efficient large-scale reconfigurable PICs on the low-temperature ICP-CVD silicon nitride platform.

中文翻译：

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采用 CMOS 兼容氮化硅制成的高能效可编程集成多端口光子干涉仪

氮化硅 ( SiN x${\mathrm{SiN}}_x$ ) 因其光损耗低而成为大规模高性能光子集成电路 (PIC) 的一种颇具吸引力的波导材料选择。然而，SiN x${\mathrm{SiN}}_x$ PIC需要高电功率才能通过微弱的热光效应实现光重构，这限制了它们在器件密度和芯片功耗方面的可扩展性。我们报告了一种在 CMOS 兼容的低温电感耦合等离子体化学气相沉积 (ICP-CVD) 氮化硅平台上工作于 1550 nm 波长的 6 模式可编程干涉仪 PIC。通过采用悬挂式热光移相器，与传统器件相比， PIC的紧凑性提高了2倍，功率效率提高了$2\times$10倍。$10\times$演示了可重构的 6 维线性变换，包括循环变换和任意酉矩阵。这项工作证明了在低温 ICP-CVD 氮化硅平台上制造高能效大规模可重构 PIC 的可行性。