Automated Highspeed Characterization of Optical Waveguides in Large-Format Glass Substrates

Fraunhofer IZM has developed a process to create low-attenuation single-mode and multi-mode waveguides in large-format thin glass using an ion-exchange technique. Given the vast number of waveguides possible on a single pane, traditional testing methods are inadequate, necessitating an automated system for efficient characterization. This paper presents a new automated attenuation measurement system designed for high-throughput evaluation of optical waveguides, including those inscribed by femtosecond lasers. The system incorporates new hardware for precise fiber-waveguide coupling and advanced image processing algorithms for feature detection on glass plates. The accompanying software interprets the optical layout, enabling the identification and measurement of specific waveguides. A novel algorithm optimizes coupling by guiding the fiber and photodiode in a spiral motion to maximize light intensity, ensuring accurate alignment and reliable attenuation measurements. This advancement significantly enhances process control and expedites the development of new manufacturing processes for optical waveguides, particularly those involving complex variable parameters like laser-written waveguides. The results presented statistically validate the process homogeneity across glass panels, marking a significant step forward in the efficiency and accuracy of optical waveguide technology in the photonic industry.