Efficient Frequency Doubling with Active Stabilization on Chip. Issue 11 (11th October 2021)

• Record Type: Journal Article
• Authors: Chen, Jia‐Yang; Tang, Chao; Jin, Mingwei; Li, Zhan; Ma, Zhaohui; Fan, Heng; Kumar, Santosh; Sua, Yong Meng; Huang, Yu‐Ping
• Is Part Of: Laser & photonics reviews. Volume 15:Issue 11(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-11
• Subjects: integrated photonics -- lithium niobate -- nonlinear optics -- Pound–Drever–Hall; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.202100091
• Languages: English
• ISSNs: 1863-8880

Abstract

Abstract: 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. Abstract : A Z‐cut, quasi‐phase matched microring and a high‐speed phase modulator are monolithically integrated on thin‐film lithium niobate nanophotonic platform. This demonstration addresses a long‐outstanding challenge facing cavity‐based optical processing, including frequency conversion, frequency comb generation, and all‐optical switching.