Unidirectional amplification in the frozen mode regime enabled by a nonlinear defect.

A stationary inflection point (SIP) is a spectral singularity of the Bloch dispersion relation ω(k) of a periodic structure where the first and the second derivatives of ω with respect to k vanish. An SIP is associated with a third-order exceptional point degeneracy in the spectrum of the unit-cell transfer matrix, where there is a collapse of one propagating and two evanescent Bloch modes. At the SIP frequency, the incident wave can be efficiently converted into the frozen mode with greatly enhanced amplitude and vanishing group velocity.

Thermo-optic VO-based silicon waveguide mid-infrared router with asymmetric activation thresholds and large bi-stability: errata.

The authors report an error in the phrasing and citation of the reference to simulation model input data in [Opt. Express31(14), 23260202310.1364/OE.

Thermo-optic VO-based silicon waveguide mid-infrared router with asymmetric activation thresholds and large bi-stability.

We report a novel four-port optical router that exploits non-linear properties of vanadium dioxide (VO) phase-change material to achieve asymmetrical power threshold response with power limiting capability. The scope of this study lies within the concept, modeling, and simulation of the device, with practical considerations in mind for future experimental devices. The waveguide structure, designed to operate at the wavelength of 5.

A reflective millimeter-wave photonic limiter.

Millimeter-wave (mm-wave) communications and radar receivers must be protected from high-power signals, which can damage their sensitive components. Many of these systems arguably can be protected by using photonic limiting techniques, in addition to electronic limiting circuits in receiver front-ends. Here we demonstrate, experimentally and numerically, a free-space, reflective mm-wave limiter based on a multilayer structure involving a nanolayer of vanadium dioxide VO, which experiences a heat-related insulator-to-metal phase transition.

Scaling theory of absorption in the frozen mode regime.

A stationary inflection point (SIP) of the Bloch dispersion relation of a periodic system is a prominent example of an exceptional point degeneracy (EPD) where three Bloch eigenmodes coalesce. The scattering problem for a bounded photonic structure supporting a SIP features the frozen mode regime (FMR), where the incident wave is converted into the "frozen mode" with vanishing group velocity and diverging amplitude. We analyze the effect of losses and disorder on the FMR and develop a scaling formalism for the absorbance in the FMR that takes into consideration losses, disorder, and system size.