Metasurfaces have been of increasing interest in the scientific community due to their consistent ability to efficiently reproduce traditional optical elements via quasi-monolithic patterning. In this dissertation I will examine various metasurfaces and methodologies for designing them, explore a computational method for designing holographic metasurfaces via discrete iterative Fourier transform, and develop the proof of concept for a device capable of detecting electromagnetic radiation in a non-traditional manner. I demonstrate that full wave numerical solvers can act as a backbone for metasurface design, enabling a wide range of possible designs based upon dielectric resonator "building blocks" evaluated in computational solvers. Full wave simulations of metasurfaces designed from these building blocks are presented. I then utilize this backbone to form a multi-step inverse process which generates a design for a holographic metasurface based on any input image. This novel program enables fast and efficient holographic metasurface design through referencing a pre-filled database, populated by simulation of metasurface building blocks. I then extend the concept of simulation based design to a novel metasurface inspired electromagnetic field detector based upon the heterodyning of plasmonic waves generated by frequency selective meta-cells. This device will function as a metasurface plasmonic beat frequency rectifier, which will provide several advantages over traditional photo-diode detectors. Some of these advantages include material design flexibility, direct wave detection which will give the possibility of phase information retrieval, and passive uncooled operation. A theoretical model, simulations, fabrication examples, and proof of concept testing will be included.