Arnab Laha

TL;DR: In this article, the formation of a special hidden singular line connecting multiple second-order hidden singular points, in a non-uniformly pumped degenerate optical microcavity, is reported.

Abstract: Exploiting scattering matrix (S-matrix) formalism, a unique route for manipulating the exceptional points (EPs) has been reported in a trilayer open optical microcavity with non-uniform real refractive index. The boundaries of the intermediate index layer are appropriately tapered. The cavity is partially pumped by a transverse distribution of a balanced gain-loss profile. With the strict restriction of balanced gain-loss, controlling infinitesimally small variation of gain-coefficient with simultaneous tapering parameter an EP has been encountered; which is being encircled in cavity parameter space to study dynamics of the coupled states around the EP in the context of robust selective flip-of-state phenomena with lower-asymmetry in state conversion efficiencies. Such a specialty trilayer microcavity with tunable width is reported for the first time; which turns out to be a specific approach to achieve maximum efficiency in conversion with minimum asymmetry. Considering suitable state-of-the-art techniques, this exclusive proposal may open up a fabrication feasible platform for device level implementation of system control exploiting EPs.

TL;DR: In this paper, a planar gain-loss assisted three-mode supported optical waveguide with local Kerr nonlinearity is proposed to explore the dynamical encirclement around multiple second-order EPs in a multistate system.

TL;DR: In this paper, a four-level parameter-dependent perturbed non-Hermitian Hamiltonian was proposed to explore the physical aspects of an EP4 analytically as well as numerically.