Efficient Frequency Doubling with Active Stabilization on Chip
Efficient Frequency Doubling with Active Stabilization on Chip
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片上有源稳定的高效倍频技术
DOI：
10.1002/lpor.202100091
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发表时间：
2021-02
影响因子：
11
通讯作者：
Jia-yang Chen;Chao Tang;Mingwei Jin;Zhan Li;Zhaohui Ma;H. Fan;Santosh Kumar;Y. Sua;Yu-Ping Huang
中科院分区：
文献类型：
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作者：
Jia-yang Chen;Chao Tang;Mingwei Jin;Zhan Li;Zhaohui Ma;H. Fan;Santosh Kumar;Y. Sua;Yu-Ping Huang
薄膜铌酸锂（TFLN）具有强的二阶非线性、快速高效的电光效应、宽的透明窗口、小的双光子吸收和自由载流子散射等特性，是集成纳米光子学的优势材料。总之，它们允许高度集成的纳米光子电路，能够通过在同一芯片上集成不同的元件来进行复杂的光子处理。然而，必须有一个证明，协同这些优越的性质为系统的优势。本文展示了一种利用TFLN有利的铁电性、高二阶非线性和强电光效应的芯片。它由一个集成了具有高质量因数的Z - cut准相位匹配微环和用于主动反馈控制的相位调制器的单片电路组成。通过Pound-Drever-Hall锁紧，仅用毫瓦的泵浦功率即可实现50%左右的稳定倍频转换。该演示解决了基于空腔的光学处理面临的长期突出挑战，包括频率转换，频率梳生成和全光开关，其稳定性能受到光折变或热效应的阻碍。这些结果进一步确立了TFLN作为一种具有光学多任务能力的优秀材料，是构建多功能芯片器件的理想材料。
Thin‐film lithium niobate (TFLN) is superior for integrated nanophotonics due to its outstanding properties in nearly all aspects: strong second‐order nonlinearity, fast and efficient electro‐optic effects, wide transparency window, and little two photon absorption and free carrier scattering. Together, they permit highly integrated nanophotonic circuits capable of complex photonic processing by incorporating disparate elements on the same chip. Yet, there has to be a demonstration that synergizes those superior properties for system advantage. Here, such a chip that capitalizes on TFLN's favorable ferroelectricity, high second‐order nonlinearity, and strong electro‐optic effects is demonstrated. It consists of a monolithic circuit integrating a Z‐cut, quasi‐phase matched microring with high quality factor and a phase modulator used in active feedback control. By Pound–Drever–Hall locking, it realizes stable frequency doubling at about 50% conversion with only milliwatt pump power. This demonstration addresses a long‐outstanding challenge facing cavity‐based optical processing, including frequency conversion, frequency comb generation, and all‐optical switching, whose stable performance is hindered by photorefractive or thermal effects. These results further establish TFLN as an excellent material capable of optical multitasking, as desirable to build multi‐functional chip devices.