Broadband High-Sensitivity Thin-Film LiNbO<sub>3</sub> Based E-Field Sensor With LF-Shaped Electrode
Yumo Tian, Shuguo Xie, Shenshen Luan, Zixian Guo, Shenda Zhang, Yan Yang
Abstract
A novel broadband high-sensitivity optical E-field sensor is proposed in this letter. To solve the problem of bandwidth sensitivity, thin-film LiNbO3 (TFLN) is employed to fabricate the photonic device. Herein, the inductively coupled plasma (ICP) etching methodology using a mixture of Ar and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{C}_{{4}}\text{F}_{{8}}$ </tex-math></inline-formula> is first introduced, which is more effective in etching and helps to sharpen the lateral angle of the LN ridge waveguide. The LF-shaped electrode is designed to improve the performance of the sensor with a bandwidth of 1 MHz to 20 GHz and a sensitivity of 1 mV/m. The volume of the sensor with the package is only <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${20}\times {5} \times 5$ </tex-math></inline-formula> mm, which can be utilized in narrow spaces of the weak electromagnetic signal in the wideband frequency range.