Photonic Integrated Transmitter for Brillouin Optical Time‐Domain Analysis

ABSTRACT Brillouin optical time‐domain analysis (BOTDA) is a powerful distributed fiber‐optic sensing technique, widely used in various fields. However, its widespread adoption is hindered by bulky and costly discrete‐component systems. Photonic integration technology offers a compelling solution to this challenge. In this paper, we demonstrate a highly integrated BOTDA transmitter, realized through the hybrid integration of an indium phosphide (InP) distributed feedback (DFB) laser chip with a silicon‐on‐insulator (SOI) photonic integrated circuit (PIC). This in‐house‐designed SOI PIC comprises three main functional sections: light selection and distribution, pump light generation, and probe light generation. The integrated BOTDA transmitter supports various modulation schemes, while a conventional single‐pulse configuration is adopted in this work for system performance evaluation. A Brillouin frequency shift (BFS) uncertainty of is achieved over a standard single‐mode fiber, with a spatial resolution (SR) of and 1000 times of averaging. At a higher SR of , a BFS uncertainty of is realized over a sensing fiber with 1000‐time averaging. To the best of our knowledge, this work presents the first dedicated on‐chip BOTDA transmitter, offering a promising path toward compact, scalable, and cost‐effective BOTDA solutions.