Gap solitons with null-scattering

We study excitation of gap solitons under the conditions of coherent perfect absorption (CPA). Our system consists of a symmetric periodic structure with alternating Kerr nonlinear and linear layers, illuminated from both the ends. We show near-total transfer of incident light energy into the gap solitons resulting in null-scattering. We also report on the nonlinear super-scattering (SS) states. Both the CPA and the SS states are shown to be characterized by typical field distributions. Both the exact and the approximate results (based on nonlinear characteristic matrix method) are presented, which show good agreement

Cavity controlled spectral singularity

We study theoretically a PT-symmetric saturable balanced gain-loss system in a ring cavity configuration. The saturable gain and loss are modeled by two-level medium with or without population inversion. We show that the specifics of the spectral singularity can be fully controlled by the cavity and the atomic detuning parameters. The theory is based on the mean-field approximation as in standard theory of optical bistability. Further, in the linear regime we demonstrate the regularization of the singularity in detuned systems, while larger input power levels are shown to be adequate to limit the infinite growth in absence of detunin

Resonance State Wave Functions of 15^{15}Be using Supersymmetric Quantum Mechanics

The theoretical procedure of supersymmetric quantum mechanics is adopted to generate the resonance state wave functions of the unbound nucleus $^{15}$Be. In this framework, we used a density dependent M3Y microscopic potential and arrived at the energy and width of the 1.8 MeV (5/2$^+$) resonance state. We did not find any other nearby resonances for $^{15}$Be. It becomes apparent that the present framework is a powerful tool to theoretically complement the increasingly important accelerator based experiments with unbound nuclei.Comment: 5 pages, 4 figures, Phys. Lett. B (2017

Nonlinearity Induced Critical Coupling

We study a critically coupled system (Opt. Lett., \textbf{32}, 1483 (2007)) with a Kerr-nonlinear spacer layer. Nonlinearity is shown to inhibit null-scattering in a critically coupled system at low powers. However, a system detuned from critical coupling can exhibit near-complete suppression of scattering by means of nonlinearity-induced changes in refractive index. Our studies reveal clearly an important aspect of critical coupling as a delicate balance in both the amplitude and the phase relations, while a nonlinear resonance in dispersive bistability concerns only the phase

Inquiring into Entrepreneurial Orientation: Making Progress, One Step at a Time

As we think through the four papers that comprise this special issue, we cannot help but be elated at the progress made by entrepreneurial orientation (EO) scholarship over the past few decades. Indeed, it seems safe to contend that EO defies the description of entrepreneurship research as a “hodgepodge” (Shane & Venkataraman, 2000), and instead serves as a good example of how a cumulative body of knowledge should develop in organizational science