A very interesting class of metamaterials can be defined making use of supersymmetry (SUSY). What makes SUSY very attractive for the design of new optical devices is the possibility to define different spatial refractive index distributions (superpartners) having the same scattering spectra (angularly and spectrally). In this study we explore the possibilities offered by the generation of superpartners of a constant (in space) refractive index distribution (practically an infinite slab), being transmissionless and possessing unit reflection by definition. Interestingly, starting from a critical wavelength, the Darboux transform allows to define 1D materials that are transmissionless (or perfectly reflective) for a continuum of frequencies and incident directions. This behavior can be understood in analogy to total reflection instead realized spectrally. In addition, broken-SUSY can be used to define a transmissionless active cavity capable of amplifying (or absorbing) electromagnetic radiation in the visible. This approach is analytical through the use of the Darboux transform (a type of supersymmetric transformation) for the generation of the optical potential and the calculation of the field, while the transmission/reflection spectra evaluation is done with the transfer matrix method. Finally, the calculated refractive index distributions can be realized in practice as 1D multi-layered structures corresponding to optical filters.
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