Simpler, faster, and softer: towards broad application of Laser Speckle Imaging in art conservation and soft matter

Uittreksel

"Laser Speckle Imaging (LSI) is a technique that employs interference of laser light to visualize motion inside materials. Based on the interference of visible light, it can detect motion as small as a few to hundreds of nanometers. LSI is also unique because it is an optical technique that requires an opaque material. Most light-based methods require a transparent material to be able to visualize the inside structure. However, most daily-life materials are not transparent, so their inner structure is not easily studied with optical methods. LSI was originally developed as a medical imaging tool to visualize the motion of red blood cells in veins. It has also been applied in materials science, but only in a few research groups over the world. While most optical methods visualize structure in semi-transparent materials, LSI visualizes dynamics in opaque materials, and does so with unparalleled sensitivity. The hardware required to perform LSI is relatively simple, just a laser and camera pointed at the same location on the sample surface. With this combination of yielding unique information, while being an experimentally accessible technique, it is surprising that LSI is not more widely applied. In this thesis we explore a few adaptations to LSI that will help to make it more accessible. We also explore new applications in the fields of art conservation and soft matter science to show the techniques potential and inspire an even broader application ... In the General Discussion we reflect on the progress we made to making LSI more accessible, and discuss potential applications, limitations and how to proceed. A major part of this chapter is an approach to extend LSI to 3D-imaging. We have made technical progress and we have shown a few examples of potential applications for LSI in this thesis. Although our work may help in making LSI more accessible, we mainly hope to inspire application in other fields by showing what is possible." -- Pages 183 and 185.