Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.31941

RADICAL: Reconfiguration-Aware Direct-Connect AI Cluster using Spatial-and-Wavelength Selective Switching

Brett George·Weiyang Wang·Yuyang Wang·Zhenguo Wu·S. C. Mancas·Xiang Meng·Manya Ghobadi·Keren Bergman
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present RADICAL, the silicon-photonic-enabled Reconfiguration-Aware Direct-Connect AI Cluster that integrates a custom spatial-and-wavelength selective switch (SWSS) with the Linux network stack. RADICAL deploys a packaged 4x4x4$λ$ microring-based SWSS into a four-GPU-server cluster using standard SFP28 optical transceivers, and a reconfiguration-aware host-networking interface to demonstrate a direct-connect reconfigurable optical fabric. The SWSS provides dynamic spatial and wavelength routing with 3.2-6.8 dB path loss, average wavelength and spatial crosstalk isolation exceeding 25 dB, and error-free 25 Gbps signal recovery across routing paths. At the system level, RADICAL validates reconfiguration-aware operation through continuous bulk data transfers totaling 6.4 TBytes over 10 minutes. We further demonstrate multitenant AI training across reconfigurable link topologies, including four ResNet-18 instances and six nanoGPT instances, with the latter sustained for more than five hours.

Explore related subjects

physics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Brett George, Weiyang Wang, Yuyang Wang, Zhenguo Wu, S. C. Mancas, Xiang Meng, Manya Ghobadi, Keren Bergman. 2026-10-22. RADICAL: Reconfiguration-Aware Direct-Connect AI Cluster using Spatial-and-Wavelength Selective Switching. https://arxiv.org/abs/2610.31941

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

KEEP EXPLORING

Related papers

arXiv2026

Volumetric Nanophotonics for Enhanced Scintillation and Remote Light Outcoupling

Nanophotonic patterning is a promising approach to enhancing light extraction in scintillator materials, with the potential to improve performance in applications such as medical imaging and particle detection. While 2D surface patterns have been successful in improving scintillator performance, the true potential of nanophotonic patterning lies in the bulk, where photons are emitted, transported, and absorbed. Here, we experimentally demonstrate the enhancement and control of scintillation using 2.5D volumetric nanophotonic patterns. Using a direct femtosecond laser writing approach, we nanofabricate square lattices of air holes into the bulk of inorganic scintillators (YAG:Ce and YAG:Yb), achieving nearly subwavelength periods compared to the peak emission wavelength and depths up to hundreds of microns, which fill a large fraction of the full thickness of the bulk. Under high-energy excitation, the patterns appear up to ~3.5$\times$ brighter and demonstrate emission enhancement trends consistent with well-established nanophotonic scaling laws. We also report a novel functionality we call "remote outcoupling," in which the nanophotonic patterns emit light that is generated in another region of the scintillator, without being directly excited themselves. Our monolithic nanofabrication approach extends nanophotonic scintillators into the bulk, which is an important step towards total control over scintillation using photonic design.

physics.optics↗
arXiv2026

Nonreciprocal coupling enables tunable exceptional-point response in non-Hermitian circuits

Exceptional points (EPs) exhibit characteristic square-root spectral responses to weak perturbations, with response magnitudes governed by configuration-dependent prefactors that are often relatively small. Modulating these prefactor while preserving the exceptional characteristics offers an additional degrees of freedom for engineering non-Hermitian sensing responses. Here, we report a nonreciprocal non-Hermitian circuit system with gyrator-meditated coupling that supports a continuous family of EP configurations. Unlike reciprocal coupling, which typically yields a unique EP configuration for balanced gain and loss, nonreciprocal coupling allows the directional forward and backward coupling strengths to be varied while maintaining their product and thus preserving the EP condition and yielding a library of EPs. This additional freedom enables continuous control of the frequency-splitting magnitude without modifying the square-root characteristic dependence on absolute perturbation strength. We show that the spectral splitting induced by a given absolute resistance perturbation can be enhanced by appropriately adjusting the coupling asymmetry. Theoretical predictions, circuit simulations, and experimental reflection-spectrum measurements consistently confirms this tunable response. Our results establish nonreciprocal coupling as an alternative approach for engineering and enhancing EP-induced perturbative responses without changing their characteristic branch-point scaling.

physics.optics↗
arXiv2026

Spatial-Mode Selection for Local Mineral Absorption Spectroscopy

Absorption-band depth measures the fractional decrease in mineral reflectance below its local continuum. Recovering this feature strength for a small mineral region supports quantitative comparisons between regions, but diffraction mixes its light with the surroundings. Conventional spectral fitting can separate mean contributions; it cannot remove background photon noise already recorded. We develop a quantum-inspired measurement framework that uses spatial-mode demultiplexing (SPADE) to retain the target absorption response while reducing background acceptance before detection. The framework connects finite mineral-region geometry and reference spectra to estimation precision. A loss-dependent design condition identifies when adding SPADE exposure improves on direct imaging (DI) under fixed-response Poisson measurements with unknown scene parameters. Joint inference from initial DI observations and both mode ports estimates target depth together with an unknown, spatially shared background spectrum. In equal-time simulations that include localization uncertainty, alignment time, calibration, and detector costs, this acquisition reduces depth root-mean-square error (RMSE) by 14\%--26\% across five absorption strengths relative to all-pixel DI with the same background freedom. These results use a supplied target feature shape and geometry, with target continuum slope fitted and curvature fixed. The analysis separates optical selectivity from parameter ambiguity and acquisition cost, providing a quantitative basis for spatial-mode receiver design in local mineral spectroscopy.

physics.optics↗