Emittance and absorptance tailoring by negative refractive index metamaterial-based Cantor multilayers

We investigated electromagnetic wave propagation through one-dimensional stacks of alternating positive and negative refractive index layers arranged as truncated quasi-periodic (fractal) Cantor multilayers. We considered the occurrence of phase compensation in these structures. In our calculation we utilized the transfer matrix technique and applied the Kirchhoff's second law to calculate emittance and absorptance modification by negative index metamaterials. We took into account dispersion and absorptive losses and analysed both on-axis and off-axis radiation. We showed that Cantor structures formed by inserting negative refractive index layers as a substitution part in the multilayer lattices enable tailoring of both spectral and angular dependences of emittance/absorptance. We conclude that phase compensation could significantly extend the applicability of Cantor-type multilayers containing negative refractive index materials.