Department of Mathematics2024-11-0920170146-959210.1364/OL.42.0052502-s2.0-85038210896https://hdl.handle.net/20.500.14288/3560We offer a simple route to perfect omnidirectional invisibility in a spectral band of desired width. Our approach is based on the observation that in two dimensions a complex potential v(x; y) is invisible for incident plane waves with a wavenumber not exceeding a pre-assigned value a, provided that its Fourier transform with respect to y, which we denote by v (x; R-y), vanishes for R-y <= 2a. We can fulfill this condition for potentials modeling the permittivity profile of an optical slab. Such a slab is perfectly invisible for any transverse electric wave whose wavenumber is in the range [0; a]. Our results also apply to transverse magnetic waves propagating in a medium with a relative permittivity epsilon (x; y) that is a smooth bounded function with a positive real part.pdfOpticsJournal Article1539-4794https://doi.org/10.1364/OL.42.005250000418019100051Q2NOIR01486