We propose and demonstrate a Mach-Zehnder modulator in Z-cut lithium niobate thin film (LNTF) with a vertical electric field structure. By placing the metal electrodes on top and bottom of the waveguide rather than the usual lateral configuration, the electric field is fully overlapping the optical field. Such a configuration reduces the critical requirement of electrode alignment as needed in X/Y-cut LN based devices. Both the simulation and process details to realize the proposed device are demonstrated. The measured static performance accords well with the simulations. Additionally, we developed a new method to accurately characterize the dynamic performance of the Z-cut LNTF modulator, and the measured tuning efficiency is around 8.84 pm/V. Our proposed device validates the feasibility of integrated Z-cut LNTF based modulators, and will likely extend the research area of integrated lithium niobate photonics.

中文翻译：

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垂直结构Z切铌酸锂薄膜集成电光调制器


我们提出并演示了一种具有垂直电场结构的 Z 切割铌酸锂薄膜 (LNTF) 中的马赫-曾德调制器。通过将金属电极放置在波导的顶部和底部而不是通常的横向配置，电场与光场完全重叠。这种配置降低了基于 X/Y 切割 LN 的器件中所需的电极对准的关键要求。演示了实现该设备的仿真和工艺细节。测量的静态性能与模拟结果非常吻合。此外，我们开发了一种新方法来准确表征 Z 切 LNTF 调制器的动态性能，测得的调谐效率约为 8.84 pm/V。我们提出的器件验证了集成 Z 切 LNTF 调制器的可行性，并可能扩展集成铌酸锂光子学的研究领域。