Optical design for high-resolution imagers

Optical imagers have become an everyday commodity over the years as smartphone users possess several of them implemented in their devices. Furthermore, in other domains imagers play a major role as in machine vision for in-line sorting or in autonomous vehicles. In many of these applications, the information to be collected by an imager goes far beyond a simple two-dimensional RGB image. Besides the spectral content of light, also its specific polarization state contains useful information. Therefore, novel advanced imagers are being investigated to record more information than merely the color of a scene, and this with high speed and extremely high spatial resolution. Within this PhD, we address many of these features by developing imagers beyond the state of the art. It is our target to record data and images close to the diffraction limit with high speed, and broad spectral and high polarization sensitivity while keeping optical losses at a minimum. Within this multi-stage effort, this thesis is focusing on the optical part of the imager, specifically on the optical design and characterization of nanostructured light directors and absorbers. This PhD consists of two parts: optical simulation and characterization. In the first part, we will define the relevant target parameters to ensure an efficient development process. We will perform optical modelling using ray tracing, finite difference time domain and other methods to develop and optimize optical nanostructures and full devices. Selected structures are going to be fabricated at Imec in 200mm and 300mm clean room facilities according to the specifications based on the simulations results. In the second part, we will build and use optical setups for the characterization of the test structures. Starting from existing optical systems in the Imec labs and in labs nearby at the university (KU Leuven), we will evaluate imagers and parts of imagers concerning their optical and electro-optical response to determine their capabilities for advanced spectral, polarization and temporal resolution. It is our goal to apply the results in imagers with recording element dimensions below the wavelength of light.