Ultra-efficient frequency comb generation in AlGaAs-on-insulator microresonators
Ultra-efficient frequency comb generation in AlGaAs-on-insulator microresonators
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DOI：
10.1038/s41467-020-15005-5
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发表时间：
2020-03-12
影响因子：
16.6
通讯作者：
Bowers, John E.
中科院分区：
文献类型：
--
作者：
Chang, Lin;Xie, Weiqiang;Bowers, John E.
非线性光学的最新进展彻底改变了集成光子学，为广泛的新应用提供了片上解决方案。目前，现有的集成非线性光子器件主要基于介电材料平台，例如Si 3 N4和SiO2。虽然半导体材料具有高得多的非线性系数和方便的有源集成，但它们具有高波导损耗，这阻碍了芯片上实现有效的非线性工艺。在这里，我们挑战这一现状，并展示了一个低损耗的绝缘体上AlGaAs平台，其异常色散和质量（Q）因子超过1.5 x 10（6）。这样一个高品质因数，结合高非线性系数和小模式体积，使我们能够证明克尔频率梳阈值只有类似于36 μ W的谐振器中的1太赫兹自由光谱范围，类似于100倍，低于以前的半导体平台。此外，具有宽的跨度（>250 nm）的梳已经产生了类似于300 μ W的泵浦功率，这是低于国家的最先进的电介质微梳的阈值功率。首次在AlGaAs谐振腔中观察到了孤子-台阶跃迁。
Recent advances in nonlinear optics have revolutionized integrated photonics, providing on-chip solutions to a wide range of new applications. Currently, state of the art integrated nonlinear photonic devices are mainly based on dielectric material platforms, such as Si3N4 and SiO2. While semiconductor materials feature much higher nonlinear coefficients and convenience in active integration, they have suffered from high waveguide losses that prevent the realization of efficient nonlinear processes on-chip. Here, we challenge this status quo and demonstrate a low loss AlGaAs-on-insulator platform with anomalous dispersion and quality (Q) factors beyond 1.5 x 10(6). Such a high quality factor, combined with high nonlinear coefficient and small mode volume, enabled us to demonstrate a Kerr frequency comb threshold of only similar to 36 mu W in a resonator with a 1 THz free spectral range, similar to 100 times lower compared to that in previous semiconductor platforms. Moreover, combs with broad spans (>250 nm) have been generated with a pump power of similar to 300 mu W, which is lower than the threshold power of state-of the-art dielectric micro combs. A soliton-step transition has also been observed for the first time in an AlGaAs resonator.