35 research outputs found
Binary image classification using collective optical modes of an array of nanolasers
Recent advancements in nanolaser design and manufacturing open up unprecedented perspectives in terms of high integration densities and ultra-low power consumption, making these devices ideal for high-performance optical computing systems. In this work, we exploit the symmetry properties of the collective modes of a nanolaser array for a simple binary classification task of small digit images. The implementation is based on a 8 × 8 nanolaser array and relies on the activation of a collective optical mode of the array—the so-called “zero-mode”—under spatially modulated pump patterns.This work was supported by a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” program (Labex NanoSaclay, Reference No. ANR-10-LABX-0035) and by Grant No. ANR UNIQ DS078. G.T. and C.M. are supported, in part, by Ministerio de Ciencia, Innovación y Universidades (Grant No. PID2021-123994NA-C22); C.M. also acknowledges funding from Institució Catalana de Recerca i Estudis Avançats (Academia). K.J. acknowledges support from the China Scholarship Council (Grant No. 202006970015).Peer ReviewedPostprint (published version
Non-Hermitian zero mode laser in a nanophotonic trimer
Symmetry-protected zero modes in arrays of coupled optical elements have
attracted considerable attention because they are expected to be robust against
coupling disorders. In the Hermitian limit, zero modes are dark ones, i.e. the
intensity in one sublattice vanishes; yet, in a non-Hermitian counterpart, zero
modes can be bright and feature {\pi}/2 phase difference between sublattices.
In this work, we report on the direct observation of a lasing zero mode in a
non-Hermitian three coupled nanocavity array. We show efficient excitation for
nearly equal pump power in the two extreme cavities. Furthermore, its
efficiency can be dynamically controlled by pumping the center cavity. The
realization of zero mode lasing in large arrays of coupled nanolasers has
potential applications in laser-mode engineering and it opens up promising
avenues in optical computing.Comment: 5 pages, 4 figure
Anti-parity-time topologically undefined state
We constructed an anti-parity-time-symmetric photonic lattice by using
perturbations. The results show the topological state will appear when the
waveguide coupling constants ; Interestingly, a state with
undefined winding numbers occurs when , in which the light
distributes only in the wide waveguides with equal magnitude distribution.
Further studies show that the edge state will be strengthened by introducing
defect for the topologically non-trivial case, while it will not affect the
equal intensity transmission for the topologically undefined state. Our work
provides a new way to realize the topological state and equally divided light
transmission and might be applicable in optical circuits and optical
interconnect
Tracking exceptional points above laser threshold
Recent studies on non-Hermitian optical systems having exceptional points
(EPs) have revealed a host of unique characteristics associated with these
singularities, including unidirectional invisibility, chiral mode switching and
laser self-termination, to mention just a few examples. The vast majority of
these works focused either on passive systems or active structures where the
EPs were accessed below the lasing threshold, i.e. when the system description
is inherently linear. In this work, we experimentally demonstrate that EP
singularities in coupled semiconductor nanolasers can be accessed and tracked
above the lasing threshold, where they become branch points of a nonlinear
dynamical system. Contrary to the common belief that unavoidable cavity
detuning will impede the formation of an EP, here we demonstrate that this same
detuning is necessary for compensating the carrier-induced frequency shift,
hence restoring the nonlinear EP in the lasing regime. Furthermore, unlike
linear non-Hermitian systems, we find that the spectral location of EPs above
laser threshold varies as a function of total pump power and can therefore be
continuously tracked. Our work is a first step towards the realization of
lasing EPs in more complex laser geometries, and enabling the enhancement of
photonic local density of states through non-Hermitian symmetries combined with
nonlinear interactions in coupled laser arrays
Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer\u27s Disease Progression
Alzheimer\u27s disease (AD) displays a long asymptomatic stage before dementia. We characterize AD stage-associated molecular networks by profiling 14,513 proteins and 34,173 phosphosites in the human brain with mass spectrometry, highlighting 173 protein changes in 17 pathways. The altered proteins are validated in two independent cohorts, showing partial RNA dependency. Comparisons of brain tissue and cerebrospinal fluid proteomes reveal biomarker candidates. Combining with 5xFAD mouse analysis, we determine 15 Aβ-correlated proteins (e.g., MDK, NTN1, SMOC1, SLIT2, and HTRA1). 5xFAD shows a proteomic signature similar to symptomatic AD but exhibits activation of autophagy and interferon response and lacks human-specific deleterious events, such as downregulation of neurotrophic factors and synaptic proteins. Multi-omics integration prioritizes AD-related molecules and pathways, including amyloid cascade, inflammation, complement, WNT signaling, TGF-β and BMP signaling, lipid metabolism, iron homeostasis, and membrane transport. Some Aβ-correlated proteins are colocalized with amyloid plaques. Thus, the multilayer omics approach identifies protein networks during AD progression
Federated learning enables big data for rare cancer boundary detection.
Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing
Federated Learning Enables Big Data for Rare Cancer Boundary Detection
Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing