Integrated photonics plays a central role in modern science and technology, enabling experiments from nonlinear science to quantum information, ultraprecise measurements and sensing, and advanced applications such as data communication and signal processing. Optical materials with favorable properties are essential for nanofabrication of integrated photonics devices. Here we describe a material for integrated nonlinear photonics, tantalum pentoxide (${{\rm Ta}_2}{{\rm O}_5}$, hereafter tantala), which offers low intrinsic material stress, low optical loss, and efficient access to Kerr nonlinear processes. We utilize ${\gt}{800}\;{\rm nm}$ thick tantala films deposited via ion beam sputtering on oxidized silicon wafers. The tantala films contain a low residual tensile stress of 38 MPa, and they offer a Kerr index of ${n_2} = 6.2 \pm 2.3 \times {10^{- 19}}\;{{\rm m}^2}/{\rm W}$, which is approximately a factor of 3 higher than silicon nitride. We fabricate integrated nonlinear resonators and waveguides without the cracking challenges that are prevalent in stoichiometric silicon nitride. The tantala resonators feature an optical quality factor up to $3.8 \times {10^6}$, which enables us to generate ultrabroad bandwidth Kerr soliton frequency combs with low threshold power. Moreover, we characterize tantala waveguides by supercontinuum generation from low-energy, ultrafast seed pulses. These demonstrations characterize future application directions with tantala integrated nonlinear photonics.

中文翻译：

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Tantala Kerr 非线性集成光子学

集成光子学在现代科学技术中发挥着核心作用，使从非线性科学到量子信息、超精密测量和传感以及数据通信和信号处理等高级应用的实验成为可能。具有良好特性的光学材料对于集成光子学器件的纳米制造至关重要。在这里，我们描述了一种用于集成非线性光子学的材料，五氧化二钽（${{\rm Ta}_2}{{\rm O}_5}$，以下简称 tantala），它具有低固有材料应力、低光损耗和有效访问克尔非线性过程。我们利用${\gt}{800}\;{\rm nm}$通过离子束溅射在氧化硅晶片上沉积的厚钽薄膜。tantala 薄膜包含 38 MPa 的低残余拉伸应力，它们提供的克尔指数为${n_2} = 6.2 \pm 2.3 \times {10^{- 19}}\;{{\rm m}^2} /{\rm W}$，大约比氮化硅高 3 倍。我们制造集成非线性谐振器和波导，而没有化学计量氮化硅中普遍存在的开裂挑战。坦塔拉谐振器的光学品质因数高达$3.8 \times {10^6}$，这使我们能够生成具有低阈值功率的超宽带宽克尔孤子频率梳。此外，我们通过从低能量、超快种子脉冲产生超连续谱来表征 tantala 波导。这些演示描述了 tantala 集成非线性光子学的未来应用方向。