Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physics
Non-Hermitian Engineering Of Single Mode Two Dimensional Laser Arrays, M. H. Teimourpour, Li Ge, Demetrios N. Christodoulides, Ramy El-Ganainy
Non-Hermitian Engineering Of Single Mode Two Dimensional Laser Arrays, M. H. Teimourpour, Li Ge, Demetrios N. Christodoulides, Ramy El-Ganainy
Ramy El-Ganainy
A new scheme for building two dimensional laser arrays that operate in the single supermode regime is proposed. This is done by introducing an optical coupling between the laser array and lossy pseudo-isospectral chains of photonic resonators. The spectrum of this discrete reservoir is tailored to suppress all the supermodes of the main array except the fundamental one. This spectral engineering is facilitated by employing the Householder transformation in conjunction with discrete supersymmetry. The proposed scheme is general and can in principle be used in different platforms such as VCSEL arrays and photonic crystal laser arrays.
Non-Hermitian Engineering Of Synthetic Saturable Absorbers For Applications In Photonics, M. H. Teimourpour, A. Rahman, K. Srinivasan, Ramy El-Ganainy
Non-Hermitian Engineering Of Synthetic Saturable Absorbers For Applications In Photonics, M. H. Teimourpour, A. Rahman, K. Srinivasan, Ramy El-Ganainy
Ramy El-Ganainy
We explore a type of synthetic saturable absorber based on quantum-inspired photonic arrays. We demonstrate that the interplay between optical Kerr nonlinearity, interference effects, and non-Hermiticity through radiation loss leads to a nonlinear optical filtering response with two distinct regimes of small and large optical transmissions. More interestingly, we show that the boundary between these two regimes can be very sharp. The threshold optical intensity that marks this abrupt “phase transition” and its steepness can be engineered by varying the number of the guiding elements. The practical feasibility of these structures as well as their potential applications in laser systems …
Supersymetric Laser Arrays, Ramy El-Ganainy, Li Ge, M. Khajavikhan, Demetrios N. Christodoulides
Supersymetric Laser Arrays, Ramy El-Ganainy, Li Ge, M. Khajavikhan, Demetrios N. Christodoulides
Ramy El-Ganainy
We introduce the concept of supersymmetric laser arrays that consist of a main optical lattice and its superpartner structure, and we investigate the onset of their lasing oscillations. Due to the coupling of the two constituent lattices, their degenerate optical modes form doublets, while the extra mode associated with unbroken supersymmetry forms a singlet state. Singlet lasing can be achieved for a wide range of design parameters, either by introducing stronger loss in the partner lattice or by pumping only the main array. Our findings suggest the possibility of building single-mode, high-power laser arrays and are also important for understanding …
Topological Tight-Binding Models From Nontrivial Square Roots, J. Arkinstall, M. H. Teimourpour, L. Feng, Ramy El-Ganainy, H. Schomerus
Topological Tight-Binding Models From Nontrivial Square Roots, J. Arkinstall, M. H. Teimourpour, L. Feng, Ramy El-Ganainy, H. Schomerus
Ramy El-Ganainy
We describe a versatile mechanism that provides tight-binding models with an enriched, topologically nontrivial band structure. The mechanism is algebraic in nature, and leads to tight-binding models that can be interpreted as a nontrivial square root of a parent lattice Hamiltonian—in analogy to the passage from a Klein-Gordon equation to a Dirac equation. In the tight-binding setting, the square-root operation admits to induce spectral symmetries at the expense of broken crystal symmetries. As we illustrate in detail for a simple one-dimensional example, the emergent and inherited spectral symmetries equip the energy gaps with independent topological quantum numbers that control the …