AI 中文总结
该研究开发了蓝宝石上超低损耗氮化硅光子集成电路平台，实现了创纪录的低损耗与高Q值，首次在该平台上产生克尔光频梳和孤子，为宽光谱非线性与量子光子学应用奠定基础。
AI 中文摘要
在过去二十年中，光子集成电路（PIC）领域蓬勃发展，推动了传感、网络、数据互连和量子信息处理等众多前沿应用。作为光子集成电路的导波材料，氮化硅（Si₃N₄）因超低损耗、宽透明范围以及可在薄膜和厚膜中实现的多样性而得到广泛应用。尽管支撑绝大多数氮化硅光子学的传统标准硅衬底上的二氧化硅（SiO₂）存在诸多缺陷：二氧化硅的长波透明范围受限、用于产生反常色散的厚膜氮化硅沉积应力高，以及低限制因子薄膜氮化硅向硅层的泄漏损耗。本研究探讨将蓝宝石衬底作为氮化硅光子学的替代基底，其具备延伸至中红外的长波透明范围、氮化硅低应力沉积以及低折射率的特性，可实现更大的光谱覆盖范围并降低制造复杂度。本研究提出了一种在500纳米厚的蓝宝石上氮化硅平台上制造超低损耗光子集成电路的可靠方法，其损耗低于0.1 dB/cm，达到了创纪录的低损耗。利用该工艺制备了固有品质因子超过4.5×10⁶的高Q微环，以及用于支持非线性增益的耦合环光子分子。凭借可实现的低损耗和高Q值，本研究进一步报道了在蓝宝石上氮化硅平台上首次实现克尔光频梳和孤子的产生。该多功能宽透明平台在损耗、品质因子和孤子产生方面的这些进展，为氮化硅光子学在先前被禁止的光谱区域开展光谱学和量子增强传感的未来工作铺平了道路，同时降低了制造复杂度。
英文摘要
The field of photonic integrated circuits (PIC) has flourished in the past two decades, fueling numerous cutting-edge applications across sensing, networking, data interconnect, and quantum information processing. As a guiding material for PIC, Si$_3$N$_4$ has seen extensive use for its ultra-low loss, broad transparency, and diversity in implementation across both thin and thick films. Although the standard, traditional silicon dioxide (SiO$_2$) on silicon (Si) substrates that underpin the majority of Si$_3$N$_4$ photonics face drawbacks in the form of long-wavelength transparency limited by SiO$_2$, high-stress deposition for anomalous dispersion thick-film Si$_3$N$_4$, and leakage loss to the Si layer for low-confinement thin-film Si$_3$N$_4$. Featuring increased long-wavelength transparency into the mid-infrared, low-stress deposition of Si$_3$N$_4$, and a low index, this work investigates sapphire substrates as alternate hosts for Si$_3$N$_4$ photonics with greater spectral coverage and reduced fabrication complexity. This work presents a robust method of fabricating ultra-low loss photonic integrated circuits on a 500-nm-thick Si$_3$N$_4$-on-sapphire platform, exhibiting record-low losses below $0.1 \rm \;dB/cm$. Implemented using this process are high-Q microrings with intrinsic quality factors in excess of $4.5\times10^6$ and coupled-ring photonic molecules to support nonlinear gain. Leveraging the achievable low loss and high-Q, this work further reports the first demonstration of Kerr-comb and soliton generation on the Si$_3$N$_4$-on-sapphire platform. These advances in loss, quality factor, and soliton generation on this versatile, broad-transparency platform pave the way for future work in spectroscopy and quantum-enhanced sensing across previously prohibited spectral regions for Si$_3$N$_4$ photonics with reduced fabrication complexity.
Comments15 pages, 6 figures
