On the TE/sub n0/ Modes of a Ferrite Slab Loaded Rectangular Waveguide and the Associated Thermodynamic Paradox

Optical Nonreciprocity Based on Optomechanical Coupling

“…(29), at the asymptotic limit Γ 0, or equivalently ∞, the forward transmission becomes 1 2 while the backward transmission approaches 1.…”

“…Asymptotically low Although the above analysis implies that it is feasible to achieve ideal isolation in a system with no optical absorption, isolation in a two-port system cannot be achieved without losses, as this operation would violate the second law of thermodynamics and realize a thermodynamic paradox [29], [30]. In this end-coupled geometry it is the coupling to the mechanical bath that provides the required losses to block propagation in the backward direction.…”

Topological Origin of Electromagnetic Energy Sinks

“…This phenomenon was previously discussed in the literature [35][36][37][38][39], but its topological origin, unveiled here by our analysis, was unnoticed. Furthermore, it is known since the 50's of last century that similar "propagation deadlocks" can be created in closed metallic waveguides partially filled with ferrites [30][31][32][33]. In particular, these pioneering studies highlighted that a wave cannot be stopped without material absorption because this would violate the third law of thermodynamics [30][31][32][33].…”

“…Furthermore, it is known since the 50's of last century that similar "propagation deadlocks" can be created in closed metallic waveguides partially filled with ferrites [30][31][32][33]. In particular, these pioneering studies highlighted that a wave cannot be stopped without material absorption because this would violate the third law of thermodynamics [30][31][32][33]. First, we numerically illustrate the emergence of an energy "sink" in systems formed by dissipative materials using full wave simulations.…”

“…Previous works demonstrated the possibility of concentrating electromagnetic energy in tight regions of space using either tapered plasmonic waveguides [27][28][29] or nonreciprocal surface waves [30][31][32][33][34][35][36][37][38][39]. Other types of electromagnetic energy sinks based on super-absorbing photonic platforms have also been proposed recently [40][41][42].…”