Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2002.12227

Tunable nonlinear spectra of anti-directional couplers

A. Govindarajan·Boris A. Malomed·M. Lakshmanan
View original source ↗Read source document ↗Export metadata ↓

Abstract

We produce transmission and reflection spectra of the anti-directional coupler (ADC) composed of linearly-coupled positive- and negative-refractive-index arms, with intrinsic Kerr nonlinearity. Both reflection and transmission feature two highly amplified peaks at two distinct wavelengths in a certain range of values of the gain, making it possible to design a wavelength-selective mode-amplification system. We also predict that a blend of gain and loss in suitable proportions can robustly enhance reflection spectra which are detrimentally affected by the attenuation, in addition to causing red and blue shifts owing to the Kerr effect. In particular, ADC with equal gain and loss coefficients, is considered in necessary detail.

Explore related subjects

physics.opticsnlin.PS

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A. Govindarajan, Boris A. Malomed, M. Lakshmanan. 2020-02-27. Tunable nonlinear spectra of anti-directional couplers. https://doi.org/10.1364/ol.388883

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Selective sparsity-enhanced synchronization in disordered semiconductor laser networks

Biological networks tend to leverage selective sparsity as an economic strategy to optimize function while minimizing wiring costs. In contrast, achieving synchronization in engineered systems such as semiconductor laser arrays is traditionally expected to require resource-intensive coupling %strong connections to overcome intrinsic frequency disorders. We demonstrate that selectively coupled sparse networks can outperform fully connected architectures, achieving near-complete synchronization with a significantly reduced coupling budget. Using an evolutionary algorithm, we identify a ``pairing opposites" principle: optimal structures specifically prioritize connections between oscillators with the largest opposite frequency detuning. This topology neutralizes dynamical interference induced by redundant links, leading to stable synchronization. We formalize this mechanism through a thermodynamic potential framework, mapping time-delayed phase dynamics to an energy landscape where optimal sparsity prunes additional states to stabilize global phase-locking. Furthermore, we show that the optimal connectivity scales inversely with system size. This principle provides a resource-efficient blueprint for synchronizing and stabilizing diverse complex networks, from photonic arrays to neuromorphic hardware.

physics.optics↗
arXiv2026

Super-resolution microscopy via fluctuation-enhanced spatial mode demultiplexing

We introduce a superresolution technique that combines spatial mode demultiplexing (SPADE) with emitter blinking. We show that temporal fluctuations not only enhance the precision of SPADE imaging, but also drastically simplify the measurement required to recover full object information---in the presence of fluctuations, SPADE can be replaced by the much simpler image inversion interferometry. Both gains are enabled by exploiting temporal cumulants of the detected signal. We further show that the proposed fluctuation-enhanced techniques are significantly more robust to dark-count noise than conventional SPADE.

physics.optics↗
arXiv2026

Phase-controlled transport of Floquet-driven compact chiral photonic states

The Aharonov-Bohm (AB) effect remains a cornerstone of fundamental and applied physics. In this work, we utilize the AB caging effect originated from an effective magnetic field induced by multiorbital interactions, creating an all flat band (FB) lattice system. Normally, FB states are known for being compact in space and having a zero tail; therefore, their mobility in a linear environment is generally understood as impossible. We propose a Floquet driving protocol in an all-FB photonic system to fully control the dynamics of localized photonic states. The modulation of the Hamiltonian along the propagation coordinate allows the translation of compact states in the direction of constructive interference, resulting in an effective stroboscopic quantum walk-like effect. We find that the traveling states exist in chiral pairs. We experimentally implement the Floquet driven protocol using femtosecond laser written photonic waveguides and demonstrate directional control of the propagation, determined by the relative phase of the input condition.

physics.optics↗