Top-hat square-mode fiber as D-shape platform for sensing

We propose to use a fiber with a nanostructured square core with a top-hat square-shaped fundamental mode. We present the results of the D-shape fiber fabrication with top-hat square-shaped fundamental mode. We will also show the numerical and experimental analysis of sensors based on such a fiber. A sensor without additional layers is only based on the study of changes in transmitted power. And, SPR and LMR sensors where a layer of metal or dielectric is deposited on the flat surface of the fiber and where the measurement is related to the change in the resonant wavelength.