Stroboscopic Inline Coherent Imaging

Abstract

Inline coherent imaging (ICI) is an in-situ monitoring technique, used in laser processing applications such as welding and additive manufacturing. Conventional ICI systems image with a continuous-wave broadband light source, which makes the system susceptible to an effect known as motion artifact. Motion artifact occurs when the interface moves over the detector exposure time, causing attenuation of the interfaces, or even a complete loss of signal when capturing high-speed motion. To address this challenge, I use stroboscopic ICI, which is a technique that involves replacing the continuous-wave (CW) imaging source with an ultrafast pulsed light source to effectively "freeze" motion. I show that stroboscopic ICI can outperform CW-ICI by increasing successful imaging rates in welding by up to 74%.