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Jonathan Barnes

Publications and source records attributed to Jonathan Barnes.

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Optoelectronic Physical Unclonable Functions and Reservoir-Inspired Computation with Low Symmetry Integrated Photonics

Emerging applications of photonics in computing, sensing, and security increasingly demand complex input-output behaviors, including highly nonlinear transformations of optical signals. Traditional photonic systems rely on highly structured components with symmetric geometries and low-entropy modal responses to achieve predictable and analytically describable behavior. To achieve expressive functionality, this paradigm often requires large networks of fabrication-sensitive interferometers or resonators and substantial hardware error correction to restore deterministic operation. Here we demonstrate an alternative paradigm rooted in low-symmetry, disordered integrated photonic circuits, which provide intrinsically enhanced modal diversity and spectral complexity, enabling highly nonlinear transformations of input signals into information-rich outputs. Our devices, physically unclonable moire quasicrystal interferometers integrated on a silicon photonics platform, exhibit aperiodic and reconfigurable spectral responses and are characterized by analyticity breaking and erasable mutual information. Using dynamic thermo-optic control to drive their complex spectral dynamics, we demonstrate that these devices function as reconfigurable physical unclonable functions (rPUFs). We also highlight their ability to perform high-dimensional input-output transformations, emulating reservoir-inspired information processing in a compact photonic platform. This work bridges the gap between engineered and natural complexity in photonic systems, revealing new opportunities for scalable, energy-efficient, and information-dense optoelectronics with applications in secure communications, hardware security, advanced sensing, and optical information processing. Our results establish low-symmetry integrated photonics as a powerful resource for complex signal manipulation in photonic systems.

physics.optics

Orbital Phase-resolved Analysis of X-ray and Gamma-ray Observations of the High-Mass Gamma-ray Binary 4FGL J1405.1-6119

We present the results of multi-wavelength observations of the High-Mass Gamma-Ray Binary 4FGL J1405.1-6119. A pair of joint XMM-Newton and NuSTAR observations taken in 2019 (sampling the gamma-ray maximum and X-ray maximum) characterize the emission of soft and hard X-rays. We find variability of the hydrogen column density along our line of sight, $N_{\rm H}$, and photon index, $\Gamma$, and find no evidence of pulsations in X-rays. We also refine a new best-fit orbital period to $P=13.7157\pm0.0014$ days, the first orbital phase-resolved analysis based on nearly 16 years of Fermi--LAT observations of 4FGL J1405.1-6119 and the evolution of the spectral shape as a function of orbital phase. Finally, the X-ray and $\gamma$-ray spectra for the phases sampled in the new X-ray observations can be interpreted in the framework of the intrabinary shock model, previously applied to High-Mass Gamma-Ray binaries such as LS 5039.

astro-ph.HE