The IPCEI (Important Projects of Common European Interest) project's overall objective is to enable research and develop innovative technologies and components (e.g. chips, integrated circuits, and sensors) that can be integrated in a large set of downstream applications. These include consumer devices, for example home appliances and automated vehicles, and commercial and industrial devices, for example the management systems for batteries used for electric mobility and energy storage. In this project, we are a third party partner of ST Microelectronics in Crolles, and are involved in a subproject that aims at exploiting nanostructuring for improving the performance of CMOS image sensor microlens array. In this context, numerical modeling is a key component for accurately characterizing the light absorption properties of these complex structures, which are multiscale by nature (from the micrometer scale of the lens to the nanometer features of the structured layers). The Finite Difference Time-Domain (FDTD) method is often adopted in the first instance for simulating light interaction with such structures. However, because it relies on a Cartesian grid, its adequacy for meshing multiscale structures, including the curvature of the microlens (at a scale of typically a micrometer) as well as the nanostructured surfaces of the silicon buffer, is limited. In this context, our main objective is to assess the capabilities of a high order finite element type time-domain from the DIOGENeS software suite for the simulation of nanoscale light-matter interaction problems involving complex structures such as those of interest to the image sensing industry.