There is a huge amount of astrophysical events that remain barely studied due to the lack of large, multiwavelength and deep optical surveys. This is the Universe at the lowest density of stars, largely unseen by past large field surveys like the Sloan Digital Sky Survey (SDSS). For instance, only a handful of galaxy clusters have been observed with enough depth to witness the intracluster light (ICL), made up of stars that drift freely between galaxies in the cluster. Thought to form by the stripping of satellite galaxies as they fall into the cluster, characterising the ICL is key to understanding the assembly mechanisms occurring inside galaxy clusters. Despite its importance, little is known about this light as it is very difficult to observe due to its low surface brightness. The availability of deep surveys have expanded our knowledge of the properties, and therefore the origin, of the ICL. However, larger samples are needed to understand the evolution of this component with time and the efficiency of the different evolutionary processes inside galaxy clusters.
In this talk, I will present the latest advances in our understanding of the ICL and the possibility to explore the dark matter distribution in galaxy clusters by using this diffuse light. I will also talk about the technical challenges of low surface brightness imaging, the lessons learned from past deep imaging that will help us to better prepare for upcoming surveys and unveil the ICL.