Guan Xiaowei, Hu Hao, Oxenløwe Leif K, Frandsen Lars H
Opt Express. 2018 Jan 22;26(2):1055-1063. doi: 10.1364/OE.26.001055.
Dense integration of photonic integrated circuits demands waveguides simultaneously fulfilling requirements on compactness, low loss, high nonlinearity, and capabilities for mass production. In this work, titanium dioxide waveguides with a thick core of 380 nm exhibiting a compact mode size (0.43 μm) and a low loss (5.4 ± 1 dB/cm) at telecommunication wavelengths around 1550 nm have been fabricated and measured. A microring resonator having a 50 μm radius has been measured to have a loaded quality factor of 53500. Four-wave mixing experiments reveal a nonlinear parameter for the waveguides of 21-34 W m corresponding to a nonlinear index around 2.3-3.6 x 10 m/W, which results in a wavelength conversion efficiency of -36.2 dB. These performances, together with the potentially simple dispersion engineering to the fabricated waveguides by the post processes, yield a strong promise for the titanium dioxide waveguides applied in photonic integrated circuits, especially for nonlinear implementations.
光子集成电路的密集集成要求波导同时满足紧凑性、低损耗、高非线性以及大规模生产能力等要求。在这项工作中，已制备并测量了具有380 nm厚芯的二氧化钛波导，其在1550 nm左右的电信波长下呈现出紧凑的模式尺寸（0.43μm）和低损耗（5.4±1 dB/cm）。已测得半径为50μm的微环谐振器的加载品质因数为53500。四波混频实验表明，该波导的非线性参数为21 - 34 W⁻¹m⁻¹，对应非线性折射率约为2.3 - 3.6×10⁻²⁰ m²/W，这导致波长转换效率为-36.2 dB。这些性能，再加上通过后处理对所制备波导进行潜在简单的色散工程设计，为二氧化钛波导在光子集成电路中的应用，特别是非线性应用，带来了巨大的前景。
