bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitophagy in yeast: known unknowns and unknown unknowns
Authors: Abeliovich Hagai
Published: October 2023

Mitophagy, the autophagic breakdown of mitochondria, is observed in eukaryotic cells under various different physiological circumstances. These can be broadly categorized into two types: mitophagy related to quality control events and mitophagy induced during developmental transitions. Quality control mitophagy involves the lysosomal or vacuolar degradation of malfunctioning or superfluous mitochondria within lysosomes or vacuoles, and this is thought to serve as a vital maintenance function in respiring eukaryotic cells. It plays a crucial role in maintaining physiological balance, and its disruption has been associated with the progression of late-onset diseases. Developmentally induced mitophagy has been reported in the differentiation of metazoan tissues which undergo metabolic shifts upon developmental transitions, such as in the differentiation of red blood cells and muscle cells. Although the mechanistic studies of mitophagy in mammalian cells were initiated after the initial mechanistic findings in Saccharomyces cerevisiae, our current understanding of the physiological role of mitophagy in yeast remains more limited, despite the presence of better-defined assays and tools. In this review, I present my perspective on our present knowledge of mitophagy in yeast, focusing on physiological and mechanistic aspects. I aim to focus on areas where our understanding is still incomplete, such as the role of mitochondrial dynamics and the phenomenon of protein-level selectivity.
Measuring Prosodic Entrainment in Conversation: A Review and Comparison of Different Methods
Authors: Kruyt Joanna , de Jong Dorina , D'Ausilio Alessandro , Beňuš Štefan
Published: October 2023

Purpose:

This study aims to further our understanding of prosodic entrainment and its different subtypes by analyzing a single corpus of conversations with 12 different methods and comparing the subsequent results.

Method:

Entrainment on three fundamental frequency features was analyzed in a subset of recordings from the LUCID corpus (Baker & Hazan, 2011) using the following methods: global proximity, global convergence, local proximity, local convergence, local synchrony (Levitan & Hirschberg, 2011), prediction using linear mixed-effects models (Schweitzer & Lewandowski, 2013), geometric approach (Lehnert-LeHouillier, Terrazas, & Sandoval, 2020), time-aligned moving average (Kousidis et al., 2008), HYBRID method (De Looze et al., 2014), cross-recurrence quantification analysis (e.g., Fusaroli & Tylén, 2016), and windowed, lagged cross-correlation (Boker et al., 2002). We employed entrainment measures on a local timescale (i.e., on adjacent utterances), a global timescale (i.e., over larger time frames), and a time series–based timescale that is larger than adjacent utterances but smaller than entire conversations.

Results:

We observed variance in results of different methods.

Conclusions:

Results suggest that each method may measure a slightly different type of entrainment. The complex implications this has for existing and future research are discussed.
Proprioceptive Acuity Influences Speech Motor Control in Healthy Adult Talkers
Authors: Nip Ignatius S. B. , Arias Carlos R. , Corcoran Jennise , Ishihara Nicole , Goble Daniel J.
Published: October 2023

Purpose:

Somatosensory feedback, including proprioception, is important for speech production. This study evaluates proprioceptive acuity of the tongue using a position-matching task and determining if proprioceptive acuity impacts speech motor control in healthy adult talkers.

Method:

Twenty-five young adults with no history of speech, language, or hearing disorders had their tongue movements recorded with an electromagnetic articulograph while completing a position-matching task. Participants were also asked to repeat two sentences that differed in the somatosensory feedback obtained. One sentence provided both tactile and proprioceptive feedback, whereas the other primarily provided proprioceptive feedback.

Results:

Participants ranged in proprioceptive acuity as measured by the position-matching task. Talkers with smaller position-matching errors and, therefore, higher proprioceptive acuity had smaller movements and slower speeds for both sentences. Talkers with lower proprioceptive acuity had reduced speech movement stability for the sentence that primarily provides proprioceptive feedback.

Conclusion:

Proprioceptive acuity of the tongue can be evaluated using a position-matching task, and acuity is associated with more efficient speech movements and greater speech movement stability, particularly when producing utterances that provide less tactile feedback.

Supplemental Material:

https://doi.org/10.23641/asha.24293740
Do Not Cut Off Your Tail: A Mega-Analysis of Responses to Auditory Perturbation Experiments
Authors: Miller Hilary E. , Kearney Elaine , Nieto-Castañón Alfonso , Falsini Riccardo , Abur Defne , Acosta Alexander , Chao Sara-Ching , Dahl Kimberly L. , Franken Matthias , Heller Murray Elizabeth S. , Mollaei Fatemeh , Niziolek Caroline A. , Parrell Benjamin , Perrachione Tyler , Smith Dante J. , Stepp Cara E. , Tomassi Nicole , Guenther Frank H.
Published: October 2023

Purpose:

The practice of removing “following” responses from speech perturbation analyses is increasingly common, despite no clear evidence as to whether these responses represent a unique response type. This study aimed to determine if the distribution of responses to auditory perturbation paradigms represents a bimodal distribution, consisting of two distinct response types, or a unimodal distribution.

Method:

This mega-analysis pooled data from 22 previous studies to examine the distribution and magnitude of responses to auditory perturbations across four tasks: adaptive pitch, adaptive formant, reflexive pitch, and reflexive formant. Data included at least 150 unique participants for each task, with studies comprising younger adult, older adult, and Parkinson's disease populations. A Silverman's unimodality test followed by a smoothed bootstrap resampling technique was performed for each task to evaluate the number of modes in each distribution. Wilcoxon signed-ranks tests were also performed for each distribution to confirm significant compensation in response to the perturbation.

Results:

Modality analyses were not significant (p> .05) for any group or task, indicating unimodal distributions. Our analyses also confirmed compensatory reflexive responses to pitch and formant perturbations across all groups, as well as adaptive responses to sustained formant perturbations. However, analyses of sustained pitch perturbations only revealed evidence of adaptation in studies with younger adults.

Conclusion:

The demonstration of a clear unimodal distribution across all tasks suggests that following responses do not represent a distinct response pattern, but rather the tail of a unimodal distribution.

Supplemental Material:

https://doi.org/10.23641/asha.24282676
A multistage distributionally robust optimization approach for generation dispatch with demand response under endogenous and exogenous uncertainties
Authors: Huang Yiwen , Huang Wentao , Tai Nengling , Li Canbing , Li Ran , Yu Moduo
Published: October 2023

Decision‐dependent (endogenous) uncertainties (DDUs), as a new type of uncertainties revealed recently, couple dispatch decisions with uncertainty parameters and thus render power system dispatch more challenging. However, most previous works handled various DDUs via stochastic programming (SP) or robust optimization (RO) in a two‐stage framework, which undoubtedly introduces the drawbacks of SP and RO, and cannot meet the nonanticipativity requirements in power scheduling. In this paper, a multistage distributionally robust optimization (DRO) method for generation dispatch with demand response (DR) is proposed considering the DDUs of deferrable loads and the decision‐independent (exogenous) uncertainties (DIUs) of wind power and regular loads. By analyzing the structure of decision‐dependency parameters, a novel data‐driven decision‐dependent ambiguity set is proposed, which provides a generic framework for formulating DDUs and DIUs simultaneously. Then a multistage DRO model with nested max‐min structure is developed to integrate the merits of DRO and nonanticipativity into generation dispatch. The proposed model is solved by tailored reformulation method and improved stochastic dual dynamic integer programming (SDDiP). Case studies illustrate the effectiveness of the proposed approach by comparing with the multistage SP, RO, and decision‐independent DRO methods.
Experimental verification of passive radar space object detection with a single low‐frequency array radio telescope
Authors: Jędrzejewski Konrad , Malanowski Mateusz , Kulpa Krzysztof , Pożoga Mariusz
Published: October 2023

The paper focuses on the results of experimental research on the possibility of passive space object detection using a single radio telescope from the European Low‐Frequency Array (LOFAR) network of astronomical radio telescopes. Commercial digital television (DVB‐T) transmitters were used as illuminators of opportunity in this radar system. In the conducted experiments, one LOFAR radio telescope served both as a surveillance receiver and reference receiver in a passive radar system. The greater part of the LOFAR telescope array was used to observe a space object, while a small part of the array was directed towards the illuminator of opportunity to record the reference signal. One of the most important problems to overcome with utilising the LOFAR radio telescope in such a solution was the effective suppression of the direct‐path component in a surveillance signal coming from the illuminator of opportunity, which was relatively close to the LOFAR radio telescope. The results regarding the passive detection of the International Space Station, included in the paper, confirm the possibility of observing the space object flying in Low‐Earth Orbit using the LOFAR telescope or another receiving system with a similar antenna array.
Prospects and setbacks for migrating towards 5G wireless access in developing Bangladesh: A comparative study
Authors: Halder Pranto , Hassan Md. Mehedi , Rahman A. K. Z. Rasel , Akter Laboni , Ahmed Abu Shakil , Khan Shakir , Chatterjee Sajib , Raihan M.
Published: October 2023

As 4G technology served as a foundation, the emergence of 5G is now underway, ushering in a new era of connectivity. With the growing demand for seamless internet experiences, particularly in the face of escalating internet subscribers, the networking domain must evolve. Developing nations strive to align with this dynamic landscape, necessitating an upgrade that integrates internet of things (IoT), natural language processing (NLP), and artificial intelligence (AI) with network infrastructure. By enhancing networking systems with lower latency and improved scalability, 5G addresses congestion issues. This is achieved by coupling mm‐wave technology with the 5G framework through the 3rd Generation Partnership Project, significantly amplifying channel bandwidth. However, the comprehensive analysis underscores challenges in 5G implementation, encompassing aspects like distance, orientation, non‐line‐of‐sight conditions, protocol utilization, and server positioning. Drawing from a dataset provided by the University of Minnesota that illuminates the limitations of 5G implementation in select US cities, this paper extends its focus to densely populated regions in developing countries of the sub‐continent. Employing a machine learning approach, the paper delves into the constraints of 5G deployment in such areas. Ultimately, this research aims to shed light on the intricacies of 5G's implementation challenges, contributing to the discourse on enhancing network infrastructure in the evolving landscape of global connectivity.
Supercontinuum generation in ICP-CVD silicon-rich silicon nitride waveguides
Authors: Jayantha Ayesha , Andrieux Aurore , Gallet Isabelle , Finot Christophe , Hammani Kamal
Published: October 2023

Inductively coupled plasma chemical vapor deposition was used to obtain thin films of siliconrich silicon nitride with a refractive index of 2.44 at optical telecommunications wavelength. The resulting layer was patterned into a 1.6 μm wide waveguide and tested for its nonlinear behavior using a 90-fs all-fiber laser centered at 1630 nm. A significant spectral broadening is demonstrated with a supercontinuum generation from 1300 nm to 1985 nm. Simulations are in fair agreement with the experiments, assuming a nonlinear index of 2 x 10-18 m2/W.
Efficient single-etch surface grating couplers in silicon nitride platforms for telecom and datacom wavebands
Authors: Korcek Radovan , Fraser William , Medina Quiroz David , Cheben Pavel , Edmond Samson , Schmid Jens H. , Milanizadeh Mazyiar , Alonso-Ramos Carlos , Vivien Laurent , Ye Winnie N. , Benedikovic Daniel
Published: October 2023

We present designs and experiments of single-etched amorphous silicon (α-Si) surface grating couplers on a silicon nitride (SiN) waveguide, operating at the telecom (C-band) and datacom (O-band) wavebands. SiN-only grating couplers demonstrate experimental coupling loss of -3.9 dB at 1.55 μm wavelength with a 1-dB bandwidth of 37 nm. Utilizing the hybrid α-Si/SiN platform with subwavelength grating structure, we obtain improved coupling performances, with the optimized fiber-chip coupling loss of -2.0 dB and a 1-dB spectral bandwidth of 42 nm centered at 1.31 μm.
Photonic-chip integrated large-mode-area high-power CW optical amplifier
Authors: Gaafar Mahmoud A. , Wang Kai , Ludwig Markus , Wildi Thibault , Lorenzen Jan , Francis Henry , Geiselmann Michael , Sinobad Milan , Kärtner Franz X. , Garcia-Blanco SoniaM. , Singh Neetesh , Herr Tobias
Published: October 2023

Here, we report on a CMOS-compatible thulium-doped high power continuous wave (CW) optical amplifier, leveraging large mode-area gain waveguides. The amplifier structure combines a silicon nitride waveguide above which a sputtered 1250 nm-thick thulium-doped alumina gain layer is deposited. We demonstrate >220 mW output signal power at center wavelength of 1850 nm inside a 9-cm-long amplifier. Small signal gain of >15 dB is achieved.
Arrayed Waveguide Grating Spectrometer on 2-µm-thick SOI Platform
Authors: Tippinit Janvit , Kuittinen Markku , Roussey Matthieu
Published: October 2023

32-channel arrayed waveguide grating spectrometer (AWG) at 1800 nm is demonstrated on a 2-µm-thick silicon-on-insulator (SOI) platform. The design and simulation of the device are performed using the beam propagation method (BPM) and we obtain the 3-dB channel width, channel spacing, and extinction ratio of 1.16 nm, 1.56 nm, and 5.17 dB, respectively. The AWG demultiplexer can be applied in the central part of a spectrometer which is replacing in integrated optics a prism or a grating in conventional free-space optics.
Computing Three-Dimensional Freeform Reflectors with a Scattering Surface
Authors: Kronberg Vì C.E. , Anthonissen Martijn J.H. , ten Thije Boonkkamp Jan H.M. , IJzerman Wilbert L.
Published: October 2023

We present a novel approach to computing reflectors with a scattering surface in illumination optics. A scattering model governed by a Fredholm integral equation is derived. Solving this integral relation yields a virtual specular target distribution, which we insert into a Monge-Ampère least-squares numerical solver to get a scattering reflector that yields the desired illumination.
Aberration compensation in two-dimensional reflective optical systems
Authors: Verma Sanjana , Anthonissen Martijn J.H. , ten Thije Boonkkamp Jan H.M. , IJzerman Wilbert L.
Published: October 2023

We present a novel approach to minimize aberrations in imaging systems. The energy distributions at the source and target of an optical system play a crucial role in designing freeform surfaces through illumination optics methodologies. We quantify the on-axis and off-axis aberrations using a merit function that depends on the energy distributions. The minimization of the merit function yields optimal energy distributions, which subsequently enable us to design freeform reflector surfaces that cause the least aberrations. We validate our method by testing it for two configurations, a single-reflector system with a parallel source to a near-field target, and a double-reflector system with a parallel source to a point target.
Fast Adaptive Optics in optically sectioned fluorescence microscopes for functional neuroimaging
Authors: Harms Fabrice , Mercier Mathias , Gauillaume-Manca Alice , Veilly Cynthia , Levecq Xavier , Bourdieu Laurent , Fragola Alexandra
Published: October 2023

We demonstrate how a novel approach for closed-loop Adaptive Optics (AO) specifically adapted to microscopy enables straightforward integration in Light-Sheet and Multiphoton microscopes, as well as fast aberration correction. We present corresponding experimental setups as well as first demonstrations of the benefits of the correction of sample-induced aberrations in zebrafish and mouse brain tissue, with the ultimate goal to enable high-speed, high-sensitivity functional imaging at large depths.
Quartz-Enhanced Photoacoustic Spectroscopy for One-Health
Authors: Patimisco Pietro , Zifarelli Andrea , De Palo Raffaele , Menduni Giansergio , Sampaolo Angelo , Giglio Marilena , Weih Robert , Nauschütz Josephine , Koeth Johannes , Spagnolo Vincenzo
Published: October 2023

We report on the development of Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) technology to detect 8 different air pollutants, namely CH4, NO2, CO2, N2O, CO, NO, SO2 and NH3, with the same acoustic detection module and interchangeable laser sources, to prove the modularity of the technique as well as the adaptability to different lasers. For each gas species, the fine structure of the infrared absorption bands has been simulated by using HITRAN database. Each gas species was detected with an ultimate detection limit well below their typical natural abundance in air even with a signal integration time as low as 0.1 s.
Non-invasive fabrication of plasmonic nanostructures on dielectric substrates coated with transparent-conductive oxide
Authors: Ramò Lorenzo , Giordano Maria Caterina , Ferrando Giulio , Canepa Paolo , Repetto Luca , Buatier de Mongeot Francesco , Canepa Maurizio , Bisio Francesco
Published: October 2023

Modern photonics demands for high-resolution (HR) and deterministic lithography on transparent substrates. Thermal scanning-probe lithography (t-SPL) is a mask-less approach that couples a nanoscopic patterning resolution with the possibility to perform morphological characterizations without damaging delicate substrates unlike it happens for other techniques of similar resolution. In order to operate at its maximum performances, an electric bias between the scanning micromachined cantilever and the sample is needed thereby preventing, in principle, the patterning of transparent materials (that are usually insulators). In this work we demonstrate that by intercalating an ultrathin layer of a transparent conductive oxide (TCO) between an insulating and transparent substrate and the polymeric thin layer it is possible to exploit all the benefits of t-SPL also on challenging optically transparent substrates. Taking advantage of this particular lithographic configuration, we were effectively able to obtain a family of different gold plasmonic nanostructures resonating in the spectral range from the Visible to the Near-Infrared. The ensemble of the different resonators shows optical properties that encourage their exploitation in fields like sensing and thermoplasmonics.
Compact implementation of an all-optical 1-bit full adder by coherent excitation of a single 3-µm2 plasmonic cavity
Authors: Dell’Ova Florian , Brulé Yoann , Gros Nicolas , Bizouard Justin , Shakirova Diana , Bertaux Aurélie , Narsis-Labbani Ouassila , Nicolle Christophe , Colas des Francs Gérard , Bouhelier Alexandre , Dujardin Erik
Published: October 2023

In contrast to the high performances of long-range, high-speed optical information transfer, optical information processing remains outperformed by electronic microprocessing. The two mains reasons are the lack of gain medium that hampers the development of an optical analogue of the transistor and the lack of compactness of the approaches proposed so far. Here, we demonstrate a new concept of the design of all-optical elementary computing units based on the shaping of plasmonic modal landscape in micrometric on-chip 2D cavities to realize reconfigurable Arithmetic and Logic Units (ALU). Our interconnect-free devices perform multi-bit logic gate functions in a single cavity without ALU cascading, therefore obviating loss in vias and so the need for gain to restore the binary signal. Moreover, an astute cavity design allows to reconfigure a single cavity into multiple logic functions, including a first full adder. The main challenge on the way to increasing the functional Boolean complexity is the design of the cavity shape and of the excitation/detection parameters for which an approach based on artificial intelligence will be implemented.
Surface vs bulk contribution to the second-harmonic generation in AlGaAs nanoresonators
Authors: Luan Yigong , Di Francescantonio Agostino , Zilli Attilio , Rocco Davide , Vinel Vincent , Borne Adrien , Lemaître Aristide , Biagioni Paolo , Duò Lamberto , Finazzi Marco , De Angelis Costantino , Leo Giuseppe , Celebrano Michele
Published: October 2023

We address the surface vs bulk origin of the second-order optical nonlinearity in AlGaAs nanocylinders through polarization-resolved measurements. By comparing numerical simulations accounting just for bulk second-order nonlinearity with experimental results, we show that the surface contribution to second-harmonic generation (SHG) cannot be neglected and depends on the resonant conditions of the nanocylinder. Additionally, our analysis suggests that bulk and surface SHG are competing effects, and that their interference might influence the overall efficiency.
Nanoimprinting for all-polymer electro-optic waveguide devices
Authors: Henrique Franciele , Maeder Andreas , Talts Ülle-Linda , Finco Giovanni , Pohl David , Kaufmann Fabian , Reig Escalé Marc , Elder Delwin , Dalton Larry , Grange Rachel
Published: October 2023

We performed the design and fabrication of polymer waveguide circuits, aiming for applications as electro-optic devices. Uniform waveguides with over one centimeter of length were fabricated by soft nanoimprint lithography. These multimode waveguides present a height of 3 µm and low surface roughness (2 nm), with a thin residual layer of 600 nm. Propagation losses at 1550 nm are estimated to be around 7 dB/cm.
Micro-porous aluminum nitride wick for non-photo-thermal desalination
Authors: Leung James , Feng Ji , Vuong Luat T.
Published: October 2023

Aluminum nitride is a white, hydrophilic, high-band-gap ceramic. Here we report on the light-induced evaporation of saltwater through a capillary wick composed of drop-cast microparticles. Saltwater evaporation rates are significantly higher than expected. Our results point to significant potential for this interface-driven approach in solar non-thermal desalination and water separation technologies.
Analysis of the recording of Fibonacci lenses using photopolymers with 3-D diffusion model
Authors: Bravo J. C. , Sirvent J. J. , García Vázquez J. C. , Pérez Bernabeu A. , Colomina Martínez J. , Fernández R. , Márquez A. , Gallego S.
Published: October 2023

In the present work, a 3-Dimensional diffusion model is proposed to predict the main properties of Diffractive Optical Elements (DOEs), recorded in photopolymers, including refractive index modulation and the evolution of the transverse intensity distribution. The model enables the selection of appropriate material characteristics based on the intended application of the DOE. Specifically, a PVA/AA photopolymer based on acrylamide is simulated using the proposed model, considering coverplating and index matching systems to mitigate the effects of thickness variation. In order to compare its properties using the suggested model, the simulation focuses on a Fibonacci Lens and the dependece of the intensity on the polymerization rate. Accordingly, axial intensity pattern is represented to prove the bifocal-behaviour of these diffractive lenses.
Study of the pump dependence of the emission properties of a plasmonic array nanolaser
Authors: Trevisani Mirko , Mendoza Sandoval Elizabeth , Pirruccio Giuseppe , Cesca Tiziana , Mattei Giovanni
Published: October 2023

Lattice plasmon lasers demonstrated to have many degrees of freedom useful to tailor the lasing properties, as the tuning of the morphological properties of the array or the coupling of proper emitters to band-edge states of the plasmonic crystal. Here, we present the results of the study of the lasing emission properties of a hexagonal array of aluminum nanoparticles as a function of the pumping conditions. We demonstrate how the geometrical and dynamic features of the pumping system have a significant impact on the lasing properties without affecting the temporal coherence of the emission. Moreover, by combining different pumping systems and studies at different incidence angles, the relationship between nanoarray, dye and pump has been clarified.
Effect of geometry, anisotropy and composition on the third-order optical nonlinearities of multilayer hyperbolic metamaterials -INVITED
Authors: Genchi Domenico , Dodici Francesca , Cesca Tiziana , Mattei Giovanni
Published: October 2023

Quantum technologies require advanced optical metamaterials whose properties can be tailored and controlled as desired. Hyperbolic metamaterials have great potential for applications in nonlinear nanophoton-ics, such as all-optical switching, optical limiting, mode-locking and optical sensing. In this work, we show how to obtain strong third-order optical nonlinearities in hyperbolic multilayers exploiting the effect of bulk plas-mon polaritons. We demonstrate the tunability of these properties with angle and polarization, and we propose a model to predict them. We evidence the enhancement of the nonlinear response in low-loss metamaterials.
Temperature dependence of LiTaO3 refractive index: Correction of Sellmeier equation
Authors: Mohand ousaid Safia , Chang Kai-H. , Peng Lung-H. , Boudrioua Azzedine
Published: October 2023

We report a new and more precise Sellmeier equation derived using the quasi-phase-matching curves obtained from the study of the optical parametric generation (OPG) in 1D periodically poled LiTaO3 (1D-PPLT) of different periods at low and high pump power.
Infrared tunable 5%MgO:PPLN OPO pumped by a 1-kHz sub-nanosecond microchip laser
Authors: Bruneteau Baptiste , Faure Basile , Debray Jérôme , Souhaité Grégoire , Segonds Patricia , Ishizuki Hideki , Taira Takunori , Boulanger Benoît
Published: October 2023

We built and studied a singly resonant optical parametric oscillator using a 5%MgO:PPLN partial cylinder pumped by a sub-nanosecond microlaser emitting 1064 nm at a repetition rate of 1kHz. It is continuously tunable from 1410 nm up to 4330 nm by rotating the cylinder and a total energy of several micro Joules is emitted with a beam quality factor M² lower than 3.
Hybrid MoS2/polymer nanoarrays for large-scale photon harvesting and enhanced molecular photo-bleaching
Authors: Ferrando Giulio , Gardella Matteo , Zambito Giorgio , Barelli Matteo , Chowdhury Debasree , Giordano Maria Caterina , de Mongeot Francesco Buatier
Published: October 2023

Header Two-dimensional (2D) Transition Metal Dichalcogenide semiconductors (TMDs) are a promising platform in view of developing a novel generation of optoelectronics devices and renewable photon to energy conversion technologies. However new ultra-compact photon harvesting schemes are urgently required to mitigate their poor photon absorption properties. In this work we propose a novel flat-optic solution where a few layers MoS2 film is conformally deposited on a large area (cm2) nanogrooved template. The subwavelength reshaping of the TMDs film induces the excitation of photonic Rayleigh Anomalies (RA). The latter promote a strong in-plane electromagnetic confinement and can be easily tuned over a broadband spectrum by tailoring the illumination conditions. As a demonstration of the potential of this large-area surface functionalization we employed the hybrid 2D nanopatterns as a photocatalyst in a prototype photobleaching reaction of Methylene Blue (MB) molecules. We demonstrate a strong enhancement of the photochemical MB degradation, well above a factor 2, by effectively tuning the RA mode in resonance to the molecular absorption band. Therefore, these findings pave the way to flat-optics photon harvesting schemes for boosting photoconversion efficiency in large-scale hybrid 2D-TMD/polymer layers, with a strong impact in applications ranging from waste-water remediation to new-generation photonics and renewable energy storage
Silica optical fibers for a detection of X-ray radiation
Authors: Proboštová Jana , Jarý Vítězslav , Beitlerová Alena , Nekvindová Pavla , Vařák Petr , Mrázek Jan
Published: October 2023

The special attention has been paid to visualization and monitoring of harmful radiation to quantify the radiation intensity and prevent the undesired exposition. For these purposes, so called radioluminescent materials are widely exploited. Special attention has been paid to the research of luminescence optical fibers, which can be used for a construction of distributed optical sensors. We present a versatile nanoparticle doping approach to Zn2+-doped silica optical fibers. Zinc oxide nanoparticles were applied into porous silica frit by a nanoparticle-doping method providing a preform which was drawn into an optical fiber. The maximum concentration of Zn2+ ions in the fiber was 0.78 at. % causing the refractive index reached the value of 1.459. The fiber outer diameter was 124.8 μm and the fiber core diameter was 14.9 μm matching the standard telecommunication dimension. The fibers exhibited a blue radioluminescence showing the emission maximum at 395 nm. The fiber properties make them worthy of investigation as sensing elements of distributed sensors of high energy radiation.
New co-drawing strategies for the fabrication of glass/polymer fibers
Authors: Strutynski Clément , Deroh Moise , Bizot Rémi , Evrard Marianne , Désévédavy Frédéric , Gadret Grégory , Brachais Claire-Hélène , Kibler Bertrand , Smektala Frédéric
Published: October 2023

Among the different fundamental aspects that govern the design and development of elongated multimaterial structures via the preform-to-fiber technique, material association methodologies hold a crucial role. They greatly impact the number, complexity and possible combinations of functions that can be integrated within single fibers, thus defining their applicability. In this work, co-drawing strategies to produce monofilament microfibers from unique glass-polymer associations are discussed.
β-Ga2O3 Deposited via MOCVD for Mid-Infrared Polarization Control
Authors: Ceneda Daniele , Centini Marco , Dereshgi Sina Abedini , Aydin Koray , Larciprete Maria Cristina
Published: October 2023

We performed infrared optical characterization of polycrystalline β-Ga2O3 films, in the 10-18 μm range, deposited by metal organic chemical vapor deposition on sapphire substrates. Our results show that it is possible to obtain a dominant β-phase film, with a well-defined, normal to surface z-axis orientation. These results are confirmed by reflection spectra performed at 45° incidence angle which reveals a z-phonon Reststrahlen band as a function of the incident field linear polarization.
Critical coupling in Cavity Resonator Integrated Grating Filters (CRIGFs) for SHG control
Authors: Gauthier-Lafaye Olivier , Calvez Stéphane , Monmayrant Antoine , Hemsley Elizabeth , Fehrembach Anne-Laure , Popov Evgueni
Published: October 2023

We demonstrate experimentally critical coupling for nonlinear conversion in grating-coupled Fabry-Pérot planar microcavities known as Cavity-Resonant Integrated Grating Filters (CRIGFs). Novel asymmetric designs offer Q-factors from 1000 to 7000 and allow critical coupling with maximised SHG. We developed an improved coupled-mode model for the linear and non-linear spectral response of CRIGFs which allows accurate insight on the intrinsic and coupling losses in these microcavities.
All optical controllable waveguiding structures induced by diffracting Bessel beams in a nonlinear medium
Authors: Chai Yue , Marsal Nicolas , Wolfersberger Delphine
Published: October 2023

In this work, we experimentally demonstrate the photo-inscription of complex waveguiding structures by a single diffracting Bessel beam (BB) propagating in a biased SBN crystal. Our optical platform enables all-optical control of the characteristics of such induced configurations by tailoring the parameters such as beam size, the electric field, and the input beam intensity. Our numerical results are in good agreement with our experimental work. In addition, we numerically study the interaction of two counterpropagating (CP) BBs under nonlinear conditions and the spatiotemporal dynamics of these photo-induced configurations. These results suggest more opportunities for fully controllable complex waveguiding structures and new all-optical solutions for active components in optical communication.
Spin-orbit interaction through Brillouin scattering in nanofibers
Authors: Zerbib Maxime , Romanet Maxime , Sylvestre Thibaut , Wolff Christian , Stiller Birgit , Beugnot Jean-Charles , Huy Kien Phan
Published: October 2023

Spin-orbit interactions (SOI), describing the transfer of a spin degree of freedom to an orbital angular momentum (OAM), have been widely explored in recent opto-acoustic studies for applications mainly in spintronics and for topological insulators [1]. We report the observation of SOI by Brillouin scattering in an optical nanofiber. Specifically, we describe the transfer of a spin degree of freedom from light incident to the nanofiber to an acoustic vortex with a topological charge of order 2 in the form of OAM. Coupled with the phase matching condition for the energy conservation during Brillouin scattering, it results in a backscattered wave with a spin opposite to the incident wave. This observation allows considering applications of opto-acoustic Brillouin memory based on polarization conversion through a SOI [2].
Nonlinear Photoluminescence from Patterned ITO Thin Films
Authors: Dell’Ova Florian , Malchow Konstantin , Pocholle Nicolas , Chassagon Rémi , Heintz Olivier , Colas des Francs Gérard , Dujardin Erik , Bouhelier Alexandre
Published: October 2023

ITO is a transparent conductive material commonly used in everyday life and for its potential in material research. In nonlinear optics for instance, ITO has shown great capabilities for harmonic generation in its epsilon-near-zero configuration. In this article, we demonstrate a completely new nonlinear behaviour from ITO thin layers. After a Ga-Focused Ion Beam (FIB) milling of the thin film, we observe nonlinear photoluminescence produced for tightly focused femtosecond pulses. The signal shares strong similarities with that commonly detected from noble metals. We show that the arising of this nonlinear photoluminescence originates from the radiative decay of metal-like hot electron distribution in the material and is associated to a modification of the optical properties by the Ga ions.
Broadband Biphoton Generation and Polarization Splitting in a Monolithic AlGaAs Chip
Authors: Meskine Othmane , Appas Félicien , Lemaître Aristide , Palomo José , Baboux Florent , Amanti Maria I. , Ducci Sara
Published: October 2023

Integrated quantum photonics is a key tool towards large scale quantum technologies. In this work we present an AlGaAs-based photonic circuit for the on-chip generation of broadband orthogonally polarized photons and the deterministic separation of the photons into separate spatial modes, facilitating their further use in protocols. We demonstrate that 85% of the pairs are deterministically separated by the chip over a full 60 nm bandwidth and we assess the chip operation in the quantum regime via a Hong-Ou-Mandel experiment displaying a raw visibility of 75.5% over the same full bandwidth.
Local sampling of the SU(1,1) Wigner function
Authors: Fabre Nicolas , Klimov Andrei B. , Leuchs Gerd , Sanchez Soto Luis L.
Published: October 2023

The Wigner phase-space formulation for systems possessing SU(1,1) symmetry has been defined by Seyfarth et al. [Quantum 4, 317 (2020)] tackling the difficulty in defining a suitable operational definition of the Wigner function. To further investigate this formulation, we propose a non-linear optical setup that incorporates photon-number-resolving detectors, which would enable a direct and comprehensive point-by-point sampling of the SU(1,1) Wigner function. We discuss the visualization of various two-mode quantum states and the effect of the losses in such a detection scheme.
Making entanglement between photonic Orbital Angular Momenta by Spontaneous Four Wave Mixing in an atomic vapor
Authors: Abobaker Myrann , Pruvost Laurence
Published: October 2023

Spontaneous Four Wave Mixing (SFWM) which generates photonic pairs is studied if it is addressed by optical vortices carrying an orbital angular momentum (OAM). We show that the output beams are OAM-correlated and that the entanglement depends on the 4-level scheme used to realize SFWM.
Complex interactions of breathers
Authors: Gelash Andrey , Chabchoub Amin , Kibler Bertrand
Published: October 2023

We present our recent theoretical and experimental advancements in studying complex multiple nonlinear interactions of coherent solitary wave structures on unstable background – breathers. We use the focusing one-dimensional nonlinear Schrödinger equation (NLSE) as a theoretical model. First, we describe the nonlinear mutual interactions between a pair of co-propagative breathers called breather molecules. Then with the novel approach of breather interaction management, we adjust the initial positions and phases of several breathers to observe various desired wave states at controllable moments of evolution. Our experiments carried out on a light wave platform with a nearly conservative optical fiber system accurately reproduce the predicted dynamics. In addition, we consider generalizations of the scalar breathers theory to the vector two-component NLSE describing polarized light and show examples of resonance vector breathers transformations.
Polarization attraction process in a dual-Omnipolarizer
Authors: Berti Nicolas , Guasoni Massimiliano , Fatome Julien
Published: October 2023

In this work, we investigate the nonlinear phenomenon of self-attraction of light state-of-polarization in optical fibers by means of dual-Omnipolarizers. More precisely, we compare the performance in terms of polarization attraction efficiency of two different systems: The first configuration relies on a series of two successive Omnipolarizers, whereas the second system includes an imbricated Omnipolarizer into the feedback loop of the main device. Our study reveals that for the same budget of power, the cascading of two Omnipolarizers allows to improve the performance of the polarization attraction phenomenon, leading to an output degree-of-polarization close to unity for any arbitrary polarized input signal.
Broadband Light Generation in Nonlinear Silicon Nitride Strip-Loaded Lithium Niobate Waveguides
Authors: Raevskaia Marina , Della Torre Alberto , Grillet Christian , Boes Andreas , Mitchell Arnan , Monat Christelle
Published: October 2023

This work demonstrates SiN strip-loaded lithium niobate waveguides with nonlinear optical properties, focusing on their performance when pumped at telecom wavelength. Experimental results show second and third harmonic generation in periodically poled SiN/LiNbO3. Furthermore, simulations reveal that these waveguides can be dispersion engineered to generate supercontinuum. The findings highlight the potential of SiN strip-loaded lithium niobate platform in sustaining broadband nonlinear light sources.
Multi-GHz repetition rate femtosecond electro-optic frequency comb based on one single phase modulator and non-linear processes
Authors: Ye Hanyu , Pontagnier Lilia , Cormier Eric , Santarelli Giorgio
Published: October 2023

We report on a multi-GHz repetition rate, femtosecond fiber laser operating in the burst mode, achieved by nonlinearly shaping and amplifying a phase-only modulated electro-optic comb at 1.03 μm. The system delivers an average power of 1.2 W with pulses compressible down to sub 100 fs.
L-band dual-comb based on gain-switched lasers for CO2 monitoring
Authors: Monroy Laura , Quevedo-Galán Clara , Pérez-Serrano Antonio , Tejero Jose Manuel G. , Esquivias Ignacio
Published: October 2023

This paper reports the development of a dual-comb spectroscopy system based on gain-switched single-mode laser diodes emitting at 1572 nm. The switching is performed by a train of short electrical pulses at a repetition rate of 100 MHz while the lasers are subjected to external optical injection. Under these conditions, broad and Hat optical frequency combs (OFC) are generated, showing 500 tones within 10 dB and a line spacing fix ed by the repetition rate of the swi tching pulses. The dual-comb gene rated by th e interference of two such combs with slightly different line spacing, is used for measuring the absorption line of CO2 at 1572.02 nm. The transmission spectrum is analyzed and fitted to a Voigt profile. A deviation of 3% in the residuals of the fitting is obtained, denoting the high spectral performance of the spectroscopy system.
Coherent averaging quantum cascade laser based dual-comb spectrometer with near infrared light illumination control
Authors: Parriaux Alexandre , Komagata Kenichi N. , Bertrand Mathieu , Hillbrand Johannes , Wittwer Valentin J. , Faist Jérôme , Südmeyer Thomas
Published: October 2023

We present a dual-comb spectrometer based on quantum cascade lasers operating at 7.7 µm with a stabilization scheme that enables coherent averaging. We show that by illuminating a low cost near-infrared light source of the front facet of the quantum cascade laser, we can tightly lock one comb line of the dual-comb spectrum, resulting in narrow linewidth with sub-radian integrated phase noise for all RF comb lines.
Bi-directional frequency shifting loops for real-time processing of broadband RF signals
Authors: Bourdarot Guillaume , Berger Jean-Philippe , Guillet de Chatellus Hugues
Published: October 2023

Analog photonic techniques can perform better than conventional digital electronics, which have significant limitations when it comes to processing fast RF signals on the fly. We show that a simple photonic architecture, based on a bi-directional frequency-shifting loop, makes it possible to calculate in real time the cross-correlation function of two broadband signals for about 200 values of their delay simultaneously. Additionally, our architecture also enables to perform spectral analysis of signals with 16 GHz instantaneous bandwidth, 100 % probability of interception, and detection electronics below 10 MSa/s.
Surface-emitting THz quantum cascade laser frequency comb with tunable external mirror dispersion compensation
Authors: Digiorgio Valerio , Senica Urban , Micheletti Paolo , Beck Mattias , Faist Jérôme , Scalari Giacomo
Published: October 2023

We present a surface emitting THz quantum cascade laser frequency comb with an adjustable chromatic dispersion compensation via a mechanically tunable GTI cavity. Surface emission and high optical feedback into the laser cavity are achieved by a planarized ridge waveguide design with low reflectivity facets and two broadband patch array antennas for coupling to an external mirror (back side) and for power extraction (front side). We demonstrate direct and reproducible manipulation of the frequency comb state, specifically the comb stability and beatnote frequency tuning, by controlling the position of an external movable mirror.
Ultrafast thin-disk laser oscillators as driving sources for high harmonic generation
Authors: Drs Jakub , Müller Michael , Trawi Firas , Modsching Norbert , Wittwer Valentin J. , Südmeyer Thomas
Published: October 2023

Thin-disk laser oscillators can nowadays reach few tens of femtosecond pulses at gigawatt-level intracavity powers and megahertz-repetition rates becoming increasingly more powerful sources for intra-oscillator high harmonic generation (HHG). Currently, we can generate high harmonics in neon reaching photon energies of 70 eV, which we expect to increase toward 100 eV in the near future. In parallel, the achievable average and peak output powers of these oscillators in the range of 100 W and 100 MW, respectively, make these sources very promising to drive HHG in single-pass configuration after nonlinear pulse compression. Starting from transform-limited 30 to 50-fs soliton output soliton pulses of TDL oscillators, we will likely see these lasers approaching a single-cycle regime becoming highly attractive sources for attosecond science.
High energy 50 fs fiber-based laser system for high harmonics generation in solids
Authors: Boukhaoui Djamila , Idlahcen Said , Houard Jonathan , Blum Ivan , Godin Thomas , Amrani Foued , Gérôme Frédéric , Benabid Fetah , Vella Angela , Hideur Ammar
Published: October 2023

We report on a high energy ultrafast fibre laser architecture designed for high harmonics generation in solids. The laser delivering 50 fs pulses with 2.12 µJ at 1550 nm has enabled the generation of harmonics up to harmonic H5 from a magnesium oxide (MgO) bulk sample. To the best of our knowledge this is the first solid-state HHG source driven by a µJ-class few-cycle fiber laser in the mid-IR region.
Phase-matching free pulse retrieval based on plasma-induced defocusing
Authors: Béjot Pierre , Bhalavi Rishabh , Faucher Olivier , Billard Franck , Hertz Edouard
Published: October 2023

A phase-matching free pulse retrieval technique based on plasma-induced defocusing in a rare gas is presented. Based on a pump-probe setup, this technique uses a moderately intense pump laser pulse for ionizing the medium, creating in turn an ultrafast defocusing lens. While a coronagraph blocks out the probe pulse in absence of ionization, the plasma lens leads to increase the probe beam size in the far field. By measuring the spectrum of the probe propagating around the coronagraph as a function of the pump-probe delay π, a bi-dimensional trace (ω,π) is obtained. This enables to fully characterize the temporal and spectral characteristics of the probe pulse through a method that is free of phase matching constraints. Demonstrated both in the near-infrared (800 nm) and in the ultraviolet (266 nm), the present technique is potentially suited for characterizing pulses in the whole transparency region of the used gas, i.e., from the deep-ultraviolet to the far-infrared.
Investigation of the limits of the secular and Markov approximations in the dissipative dynamics of laser-aligned molecules
Authors: Bournazel Manon , Ma Junyang , Billard Franck , Hertz Edouard , Wu Jian , Boulet Christian , Hartmann Jean-Michel , Faucher Olivier
Published: October 2023

We point out the breakdown of two approximations widely used to describe decoherence in open quantum systems, the secular and Markov approximations. We probe their limits by studying the influence of pressure on the alignment revivals (echoes) created in properly chosen gas mixtures (HCl and CO2, pure and diluted in He) by one (two) intense and short laser pulse(s). Experiments, as well as predictions using molecular dynamics simulations, consistently demonstrate in some of the aforementioned systems the break-down of these approximations at very short times (<15 ps) after the laser kick(s).