Integrated photon sensor based on Ti₃C₂T_x MXene film and microgroove Mach-Zehnder Interferometer

Optical waveguide refractive index (RI) sensors have significant potential in various environmental-monitoring fields. Given the limitations of waveguide materials, enhancing the sensitivity of the optical waveguide sensors requires materials functionalization. Moreover, the sensor structure requires a specialized design to enhance its sensitivity. In this study, a hybrid optical waveguide RI sensor was used fabricated by integrating a Ti3C2Tx MXene film with a Microgroove Mach–Zehnder Interferometer (MMZI). First, the sensor arm is etched to create a microgroove structure, which enhances the interaction between the sensor arm and the external environment. Second, the agglomeration of MXene was inhibited by vacuum filtration, resulting in a large-area, self-supporting MXene membranes. Finally, an MXene self-supporting film was prepared and precisely transferred to the microgroove of the sensing arm to create a wafer-level MXene-Based Composite Waveguide Sensors. The experimental results demonstrate a linear relationship between the light intensity drift of the sensing probe and the RI change with the sensor sensitivity measured at −738 dB/RIU and a linear correlation coefficient of 0.99758. Additionally, this study employed the density functional theory (DFT) to calculate the RI parameters of the MXene materials. This type of Composite Waveguide Sensors can be mass-produced using semiconductor processing technology and has broad applications in fields such as environmental monitoring.