arXiv subjects

Kamyar Behrouzi

Publications and source records attributed to Kamyar Behrouzi.

3 recordsLinked to original sources

arXiv2026

Differential chiral sensing at exceptional points in intrinsically chiral metastructures

Discriminating opposite enantiomers through their weak chiroptical responses remains a fundamental challenge in optical sensing. Exceptional points (EPs), non-Hermitian singularities at which eigenvalues and eigenvectors coalesce, offer a route to enhanced spectral responses through their characteristic square-root eigenvalue splitting. However, their potential for chiral discrimination remains largely unexplored. We demonstrate exceptional points in an intrinsically chiral hybrid metamaterial and reveal strongly asymmetric responses to enantiomeric perturbations. The interplay between intrinsic chirality and non-Hermitian degeneracy is realized through the coupling of a chiral plasmonic nanoantenna array to a photonic crystal slab. We observe characteristic complex-square-root scaling, with both resonance frequencies and loss-rates exhibiting pronounced handedness dependence. Remarkably, opposite enantiomers produce complex mode splittings that differ by more than an order of magnitude. Our findings establish intrinsic chirality as a new degree of freedom in non-Hermitian physics and reveal a fundamental route toward topological singularities enhanced discrimination of chiral matter.

physics.optics↗

arXiv2026

AI-Assisted Hyperspectral Interferometry and Single-Cell Dispersion Imaging

Interferometry techniques are essential for extracting phase information from optical systems enabling precise measurements of dispersion and highly sensitive detection of perturbations. While phase sensing offers enhanced sensitivity compared to conventional spectroscopy methods, this sensitivity often makes systems more vulnerable to external factors such as vibrations, introducing instability and noise. In this work, we demonstrate a broadband and AI-enhanced interferometry method, denoted general polarization common-path interferometry (GPCPI) that relaxes the polarization constraints of traditional common-path interferometry. The polarization decoupling feature enables simultaneous amplitude and phase measurements supplemented with deep neural autoencoders to detect phase anomalies in the spectrum through the analysis of second order derivative mapping of the phase profile, enhancing the accuracy of broadband phase measurements. The approach enables an order of magnitude improvement in phase stability compared to state-of-the-art interferometry techniques, leading to higher accuracy in phase sensing. Plasmonic metasurface phase sensing and hyperspectral single-cell dispersion imaging demonstrate the capability and sensitivity of the method over conventional spectroscopy. Our adopted version of deep learning model, ConvNeXt V2, enables real-time tracking of phase variation with minimized noise. Interference fringes affected by the cell-cultured samples reveal the fingerprints of the normal (CCD-32Sk) vs cancerous (COLO-829) skin cells, enabling cell classification and disease diagnosis at single-cell level through hyperspectral dispersion imaging. The proposed technique offers a reliable, compact, and stable solution for broadband phase measurements and single-cell dispersion imaging for applications in metrology, molecular diagnostics, drug discovery, and quantum sensing.

physics.optics↗

arXiv2023

On the Modelling and Numerical Simulation of Non-Newtonian Blood Flow in an Aneurysm

Cardiovascular diseases, specifically cerebral aneurysms, represent a major cause of morbidity and mortality, having a significant impact on the cost and overall status of health care. In the present work, we employ a haemorheological blood model originally proposed by Owens to investigate the haemodynamics of blood flow through an aneurytic channel. This constitutive equation for whole human blood is derived using ideas drawn from temporary polymer network theory to model the aggregation and disaggregation of erythrocytes in normal human blood at different shear rates. To better understand the effect of rheological models on the haemodynamics of blood flow in cerebral aneurysms we compare our numerical results with those obtained with other rheological models such as the Carreau-Yasuda (C-Y) model. The results show that the velocity profiles for the Newtonian and the Owens models are approximately similar but differ from those of the C-Y model. In order to stabilize our numerical simulations, we propose two new stabilization techniques, the so-called N-Owens and I-Owens methods. Employing the N-Owens stabilization method enables us to capture the effect of erythrocyte aggregation in blood flow through a cerebral aneurysm at higher Weissenberg (We) and Reynolds (Re) numbers than would otherwise be possible.

physics.flu-dyn↗