Fully automatic fabrication of fibre Bragg gratings using an AI-powered femtosecond laser inscription system

TL;DR

This paper introduces an AI-driven femtosecond laser inscription system for fully automated, precise, and high-throughput fabrication of fibre Bragg gratings, overcoming manual limitations and enhancing stability and repeatability.

Contribution

The study presents an integrated AI-powered system that automates FBG fabrication with real-time position correction, improving precision, stability, and scalability over traditional manual methods.

Findings

Achieved precise laser alignment within 0.6 microns.

Fabricated FBGs with high spectral stability and repeatability.

Reduced manual intervention, enabling scalable production.

Abstract

Fibre Bragg gratings (FBGs) are widely used in optical sensing and communication systems. Femtosecond laser inscription (FLI) enables hydrogen-free, thermally stable, high-resolution, and complex structures of FBG fabrication, but its practical application is limited by manual operation, low throughput, and sensitivity to laser alignment. In this study, we present an AI-powered FLI system that enables automated, stable, and efficient FBG fabrication. By integrating a Multi-Layer Perceptron (MLP) model for real-time fabrication position correction, the system maintains precise laser alignment (-0.6 to 0.2 microns of the fibre core plane) and ensures consistent processing. Strong and weak FBGs were fabricated in different types of fibres, and their spectral characteristics-including central wavelength, reflectivity, and FWHM-exhibited high stability and repeatability. The results demonstrate that the proposed AI-powered FLI system significantly reduces manual intervention while achieving reliable FBG performance. This approach holds great promise for scalable, high-throughput FBG production and can be extended to the fabrication of arbitrary FBG structures across various fibre types. With further training and model refinement, the AI-powered FLI provides a scalable and intelligent platform for next-generation automated FBG manufacturing.