bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesoscopic Self-Collimation under oblique incidence in hexagonal-lattice mesoscopic photonic crystal
Authors: Flores Esparza SergioIván , Gauthier-Lafaye Olivier , Monmayrant Antoine
Published: October 2023

We demonstrate numerically mesoscopic self-collimation under arbitrary oblique incidence in hexagonal-lattice mesoscopic photonic crystal and propose a fast and simple methodology for design and parametric exploration of such geometries.
Resonant State Spectral expansions including bound-state contributions
Authors: Stout Brian , Ben Soltane Isam , Bonod Nicolas
Published: October 2023

Extensions of the Resonant State or (Quasi-normal mode) formalism are shown to permit unified descriptions of the true ’bound’ states within the framework of the ’leaky’ mode formulation of basis sets. We review recent progress in the famed ’normalization/regularization’ problems of the QNMs modes as well as the necessity of including ’background’ contributions whose expressions can be determined through response function sum-rules.
Design of a reflectionless optical amplifier through broken-supersymmetry
Authors: Tricoli Ugo
Published: October 2023

A very interesting class of metamaterials is characterized by supersymmetry (SUSY). What makes SUSY very attractive for the design of new optical devices is the possibility to define different spatial refractive index distributions (superpartners) having the same scattering spectra (angularly and spectrally). In this study we explore the possibilities offered by the generation of superpartners of vacuum, being reflectionless and possessing unit transmission by definition. In particular, broken-SUSY is used to define a reflectionless active cavity capable of amplifying electromagnetic radiation in the visible. The approach is analytical through the use of the Darboux transform (a type of supersymmetric transformation) for the generation of the optical potential and the calculation of the field, while the transmission/reflection spectra evaluation is done with the Transfer Matrix method. Interestingly, we show that the Darboux transform allows to define 1D materials that are reflectionless for a continuum of frequencies. Moreover, the proposed device behaves as a dynamic optical filter amplifying radiation arriving at large angles while for other directions is almost completely transparent. Thus, simply by rotation different functionalities can be obtained. In addition, the active filter is reflectionless for all wavelengths and angles of incidence.
Dielectric multilayer cavity coupled metamaterial
Authors: Guo Tian-Long , Li Fangfang , Roussey Matthieu
Published: October 2023

Dielectric multilayer stack metasurface is coupled with a gold mirror forming a hybrid metamaterial that targeting at multiband absorption. The resonant mechanisms responsible for each absorption band are explained in this study. Furthermore, a potential fabrication process has been proposed and demonstrated. This absorber exhibits flexibility in design and feasibility in fabrication, which makes it an excellent candidate for various applications, particularly in the field of sensing.
Fabrication and assessment of mechanically flexible 1D photonic crystals
Authors: Zanetti Giacomo , Carlotto Alice , Tran Thi Ngoc Lam , Szczurek Anna , Babiarczuk Bartosz , Sayginer Osman , Varas Stefano , Krzak Justyna , Bursi Oreste , Zonta Daniele , Lukowiak Anna , Righini Giancarlo , Ferrari Maurizio , Baldi Giacomo , Bonomo Matteo , Galliano Simone , Baroloj Claudia , Bazzanella Nicola , Pietralunga Silvia Maria , Chiasera Alessandro
Published: October 2023

Flexible glass photonics is a cutting-edge technological and scientific research field that, thanks to a very broad spectrum of applications, has tremendously grown during the last decade and is now a strategic topic. Here, we present the results of the spectral transmittance and reflectance of a 10-layer SiO2/TiO2 1D photonic crystal deposited on a flexible polymeric substrate under different bending conditions, obtained with a home-made adjustable sample holder.
First measurements of second-order frequency conversion phase-matching conditions in the new CTAS crystal
Authors: Remark Théodore , Segonds Patricia , Debray Jérôme , Jegouso David , Víllora Encarnación G. , Shimamura Kiyoshi , Boulanger Benoît
Published: October 2023

We report that Ca3TaAl3Si2O14 is a positive uniaxial crystal and provides second-order frequency conversion. Indeed, we performed direct measurements of phase-matching conditions for second-harmonic generation and sum-frequency generation up to 3.5 µm. The simultaneous fitting of recorded data provided the Sellmeier equations of the two principal refractive indices and the magnitude of the nonlinear coefficient.
Investigation on Subsurface Damage Patterns in Ultrashort Pulse Laser Machining of Glass using Optical Coherence Tomography
Authors: Frank Samson , Reichenbächer Maria , Seiler Michael , Arnold Thomas , Bliedtner Jens
Published: October 2023

Ultrashort pulse (USP) laser ablation is gaining popularity as a novel manufacturing technique for brittle materials, enabling the creation of complex freeform shapes that are challenging to produce with conventional optics manufacturing techniques. Freeforms have revolutionized optics manufacturing by providing designers with increased degrees of freedom using non-rotational symmetric components. However, this evolution presents new challenges for manufacturing processes, calling for innovative solutions such as USP ablation. To ensure the industrial viability of areal USP laser machining, it is crucial to not only consider material removal rates but also surface quality and subsurface damage (SSD). Especially for optical applications, harsh quality requirements must be met. This study investigates the SSD patterns of fused silica (FS) and borosilicate glass N-BK7 (BK) processed under different laser wavelengths, beam geometries and processing parameters using high-resolution optical coherence tomography (OCT). It is shown that OCT as non-destructive and 3D evaluation method is well-suited for analysing USP processes. The discovered differences in defect morphology between FS and BK emphasize the importance of selecting appropriate processes and process parameters when working with different materials. Compared to previous studies, for the parameter sets analysed here using OCT, much higher defects depths of up to 441 µm were revealed.
Capability and limits of the technology of complex optical interference filters
Authors: Moreau Antonin , Koc Cihan , Hector Olivier , Lemarchand Fabien , Lemarquis Frédéric , Lereu Aude , Lumeau Julien
Published: October 2023

Over the last 15 years, there have been tremendous progress in the technology of optical interference filters. Nowadays, it is more and more common to fabricate optical interference filters that can combine several tens to several hundreds of layers in order to produce more and more complex optical functions. These progresses are the result of improved multilayer structures modeling and design procedures, the introduction of Virtual Deposition Process, and the development of performant physical vapor deposition machines associated with in-situ optical monitoring. In this paper, we will present actual state-of-the-art of these technologies and some typical examples of filters. We will then present some of the actual challenges and outlook in order to produce more and more performant optical components.
Fabrication of Er3+ doped tellurite whispering gallery mode microsphere laser using 0.98 μm and 1.48 μm pump lasers
Authors: Thekke Thalakkal Snigdha , Ristic Davor , Zhivotkov Daniil , Nunzi Conti Gualtiero , Pelli Stefano , Ivanda Mile
Published: October 2023

We reported lasing in Er3+ doped tellurite glass whispering gallery mode microspheres fabricated using the plasma torch method.15Na2O25WO360TeO2 doped with 0.5 mol% Er3+ is used for the fabrication of microspheres. Laser light from the pump is coupled to the microsphere through a half and a full tapered fiber. An optical spectrum analyzer receives the counter propagating light from the microsphere. Pump lasers of 980 nm and 1480 nm are used to achieve the laser emission at 1570 nm.
"Talking" Vector Solitons and their Polarization Conformity in Fabry-Pérot Cavities
Authors: Hill Lewis , Hirmer Eva-Maria , Campbell Graeme , Bi Toby , Ghosh Alekhya , Oppo Gian-Luca , Del’Haye Pascal
Published: October 2023

Optical frequency combs are applicable across many fields, especially in metrology. Through accounting for field polarization, the spontaneous symmetry breaking of vector temporal cavity solitons and combs in Kerr Fabry–Perot resonators is presented. This work can improve the generation of frequency combs through its control on the maximum number of soliton-pairs in a round trip and reveals the interesting phe-nomenon of dominant polarization conformity across all soliton-pairs in the cavity.
Full-beam spatial coherence measurements of supercontinuum generation in multimode fibers
Authors: Li Jiaqi , Ryczkowski Piotr , Genty Goëry
Published: October 2023

We study experimentally the spatial coherence across the full spatial beam profile of supercontinuum light generated in both in graded-index and step-index multimode fibers. We observe a decrease of the coherence area with an increase of the injected pump power. Numerical simulations based on linearly polarized modes and mode coupling theory are in good agreement with our experiments and indicate that the decrease of coherence area is strongly related to a change in the modal amplitude distribution.
Mid-infrared generation beyond 3.5 µm in a graded-index silica fiber
Authors: Stefanska Karolina , Bejot Pierre , Fatome Julien , Millot Guy , Tarnowski Karol , Kibler Bertrand
Published: October 2023

We present theoretical as well as experimental evidence of far-detuned nonlinear wavelength conversion towards the mid-infrared, namely beyond 3.5 µm, in a few-mode graded-index silica fiber pumped at 1.064 µm. We take into account the full frequency-dependence of the propagation constants, which allows us to obtain excellent agreement of theoretical predictions with experimental observations and provides new and accurate interpretation of intramodal and intermodal four-wave mixing processes in few-mode fibers.
Development of single photon source based on micro-ring resonator for quantum memories
Authors: Durán-Gómez Juan Samuel Sebastián , Gómez-Robles Mauricio , Ramírez-Alarcón Roberto , Rodríguez-Becerra Gerardo José , Tavares-Ramírez Gerardo José , Salas-Montiel Rafael
Published: October 2023

We design a photon pair source with emission at 606 nm and 3.98 MHz linewidth, which matches the spectral properties of praseodymium ions. To reduce the linewidth the use of cavity-enhanced spontaneous four-wave mixing was proposed. The designed integrated source is suitable for praseodymium quantum memories.
Broadband cavity ring-down Fourier-transform spectroscopy
Authors: Rutkowski Lucile , Dubroeucq Romain , Charczun Dominik , Maslowski Piotr
Published: October 2023

We perform broadband cavity ring-down spectroscopy (CRDS) relying on the near-infrared frequency comb as the excitation source and a time-resolved mechanical Fourier transform spectrometer as detection device. The many decays corresponding to each spectral element are recorded simultaneously and sorted after Fourier transformation to yield the CRDS spectrum of CO in Ar contained in a 20’000-finesse cavity.
Dual-comb spectrometer in the two-micron region using a new design of dispersion-controlled highly nonlinear fibre
Authors: Malfondet Alix , Deroh Moise , Parriaux Alexandre , Ahmedou Sidi-Ely , Dauliat Romain , Labonté Laurent , Tanzilli Sébastien , Delagnes Jean-Christophe , Roy Philippe , Jamier Raphaël , Millot and Guy
Published: October 2023

We present here an experimental demonstration of dual-comb spectroscopy performed around 2 µm, with the use of a new design of dispersion-controlled highly nonlinear fibre. The latter allows us to efficiently convert light via a four-wave mixing process from 1.55 µm to 2 µm, which is a spectral region suited for the detection of pollutants such as CO2 or N2O. Experimental measurements have been performed with these two molecules and show an excellent agreement with the HITRAN database.
Mid-Infrared Frequency Combs based on Single Section Interband Cascade Lasers
Authors: Abajyan Pavel , Chomet Baptiste , Diaz-Thomas Daniel A. , Saemian Mohammadreza , Mičica Martin , Mangeney Juliette , Tignon Jerome , Baranov Alexei N. , Pantzas Konstantinos , Sagnes Isabelle , Sirtori Carlo , Cerutti Laurent , Dhillon Sukhdeep
Published: October 2023

In this work we show Frequency Comb (FC) and short pulsed operation of mid-infrared Interband Cascade Lasers (ICLs) in a single long section. This is through the use of an adapted ultrafast Quantum Well Infrared Photodetectors (QWIPs), and correlating the microwave beatnotes with high resolution spectra of the ICL. In particular, we will show active mode-locking (ML) of single -section ICL that does not require RF optimisation of the ICL device and highlight its temporal characteristics using Shifted Wave Infrared Fourier Transform Spectroscopy (SWIFTS) analysis to reconstruct the intensity in the time domain.
Tunable electro-optic frequency-comb generation around 8 µm wavelength
Authors: Turpaud Victor , Nguyen Thi-Hao-Nhi , Koompai Natnicha , Frigerio Jacopo , Coudevylle Jean-René , Villebasse Cédric , Bouville David , Alonso-Ramos Carlos , Vivien Laurent , Isella Giovanni , Marris-Morini Delphine
Published: October 2023

Electro-optic frequency-comb is an interesting method for comb generation as it offers the possibility to electrically tune the generated frequency-comb by simply tuning the electrical signal applied on the modulator. Integrated modulators operating in a wide spectral range in the mid-IR have been demonstrated recently, relying on free carrier plasma dispersion effect in a Schottky diode embedded in a Ge-rich graded SiGe waveguide. Such integrated mid-infrared modulators have been used to generate electro-optic frequency-combs with more than 200 lines around the 8 µm wavelength optical carrier.
Digital holography with microcombs
Authors: Amann Stephan , Xu Bingxin , He Yang , Vicentini Edoardo , Hänsch Theodor W. , Lin Qiang , Vahala Kerry , Picqué Nathalie
Published: October 2023

Optical microresonators are attractive comb sources due to their small form factor and stable broad optical spectra. We report on the first demonstration of microcomb-based digital holography. The large line spacing of microcombs promises an unprecedented combination of precision, fast update rate and ambiguity ranges on the scale of a few mm. Using a pulse-driven lithium niobate microcomb of 100 GHz line spacing and a scanning Michelson interferometer, we generate spectral hypercubes of holograms. Our first experimental results show that the amplitude and phase information of the object can be recovered for more than 100 comb lines.
Coherent walk and lock in driven fast-gain frequency-combs
Authors: Heckelmann Ina , Bertrand Mathieu , Dikopoltsev Alexander , Scalari Giacomo , Beck Mattias , Faist Jérôme
Published: October 2023

Locking multiple modes into a frequency comb is key for multiple metrological applications, and a great effort has been therefore invested in this challenge over the last decade. The most common techniques are based on either nonlinearities or modulation of the cavity, while the latter is considered the more controllable method to produce frequency combs. The modulation couples cavity modes and creates a lattice in a synthetic dimension with coherent walk dynamics, but typically these dynamics are overthrown by the dissipative processes, leading to a spectrum that is narrow relatively to the full frequency ladder potential. Here we propose and demonstrate that by using fast-gain we preserve the full potential of the coherent walk and lock the frequency comb at its maximum possible bandwidth. Moreover, we find in our system a unique regime of dissipative fast-gain Bloch oscillations. We demonstrate these dynamics in RF-modulated quantum cascade laser ring devices.
Dynamics of Kerr Frequency Combs in Fiber Cavity Brillouin Lasers
Authors: Deroh Moise , Lucas Erwan , Kibler Bertrand
Published: October 2023

We investigate coherent Kerr combs generation via Brillouin lasing in a non-reciprocal cavity. This approach offers adjustable repetition rates and enhanced coherence. A numerical model is presented that ac-counts for the interplay between Brillouin scattering, Kerr effect, and cavity resonant feedback. Through quan-titative agreement with experiments, our study highlights the importance of mode-pulling effects in setting the comb’s dynamics, which had been overlooked in previous fiber experiments. Finally, we discuss limitations and suggest scaling laws for these systems.
Dynamical Systems of Oscillating Ultrashort Pulse Pairs
Authors: Spector Saar , Coillet Aurelien , Colman Pierre , Grelu Philippe , Gat Omri
Published: October 2023

We propose a theoretical method to model the complex phenomenon of oscillating ultrashort pulse pair molecules. Using a phenomenological viewpoint, we construct effective dynamical systems, whose degrees of freedom are the inter-pulse timing and overall phase. The effective dynamical system is characterized by a limit cycle attractor that is fit to the experimentally measured soliton oscillation using data-driven methods. Good agreement is achieved between the dynamical system orbits and experimental observations made in a mode-locked fiber laser.
Give your optical metrology a LIFT
Authors: Porcar Rafael , Levecq Xavier
Published: October 2023

Shack Hartmann (SH) Wavefront Sensing (WFS) brings many advantages that has made it a standard in optical metrology, but it has long been limited by its resolution compared to other solutions, such as interferometry.

We will present a new approach to the linearized focal plane technique (LIFT), formerly developed by ONERA, which is based on the combination of standard SH technology with phase retrieval algorithms. Applied on all the spots of the SH wavefront sensor microlens array, it provides information on high spatial frequencies, allows to reconstruct more modes for each microlens and results in a 16-fold improvement (4x in each transverse direction) of the sensor spatial resolution!

We will present how we have optimized and validated the LIFT technology for optical metrology. We will share some measurements performed on extremely complex wavefronts. Finally, we will propose an implementation for industrial applications such as manufacturing and will describe some use cases.

Benefiting from the same advantages as SH WFS -such as robustness to vibrations and atmospheric turbulence, or the ability to easily work at any wavelength- the LIFT technology presents very promising perspectives for optical and freeform metrology and can advantageously replace, at lower cost and better usability, Fizeau interferometry.
Single-photon detector-based long-distance Brillouin optical time domain reflectometry
Authors: Romanet Maxime , Rochat Etienne , Huy Kien Phan , Beugnot Jean-Charles
Published: October 2023

We present a long-range Brillouin optical time domain reflectometer (BOTDR) based on photon counting technology. We demonstrate experimentally the ability to perform a distributed temperature measurement, by detecting a hot spot in a thermal bath at 100 km, and the possibility to achieve measurement until 120 km with a spatial resolution of 10 m. We use the slope of a fiber Bragg grating (FBG) as a frequency discriminator, to convert count rate variation into a frequency shift. A performance study of our distributed sensor as a function of spatial resolution is also presented.
Optical measurement instrument for detection of powdery mildew and grey mould in protected crops
Authors: Bouquet Grégory , Kaspersen Kristin , Haugholt Karl Henrik
Published: October 2023

This study presents an initiative aimed at developing a real-time optical measurement system for non-contact measurement of fungal spores in protected crops such as strawberries, tomatoes and cucumbers. The system is based on a customized microscope. It has been tested in the field under real conditions and image processing algorithms have been developed to identify fungal spores in high resolution microscope images.
Optoelectronic oscillator controlled by photodiode-based optoelectronic chromatic dispersion and FBG integration
Authors: Dutta Ayuushi , Glasser Ziv , Sternklar Shmuel
Published: October 2023

High Optoelectronic Chromatic Dispersion in Ge PN-type photodetectors affects the output of the Optoelectronic Oscillator. This is utilized to achieve high sensitivity wavelength monitoring and strain sensing. The sensitivity is enhanced for higher oscillating mode numbers and lower cavity lengths.
High-frequency processing effects on three commercial polymers with different thermal properties under femtosecond laser irradiation
Authors: Bernabeu Andrés P. , Nájar Guillem , Ruiz Alberto , Bravo Juan C. , Ramirez Manuel G. , Gallego Sergi , Márquez Andrés , Puerto Daniel
Published: October 2023

The response of three of the most used commercial polymers (poly(vinyl chloride) (PVC), poly(ethylene terephthalate) (PET) and polypropylene (PP)) with different thermal properties under irradiation with high frequency (1 kHz-1 MHz) femtosecond (450 fs) multi-pulse (N=10-1500) laser at λ=515 (1.34 J/cm2) and 1030 (1.70 J/cm2) is reported. Thermal and ablative effects are observed after laser irradiations. The results are compared to a photothermal model that pretends to explain the heat accumulation effect of successive pulses irradiation. Thermal analyses (Modulated Differential Scanning Calorimetry (MDSC) and Thermogravimetry (TG)) are performed and utilized to explain the different behaviour of each polymer. Three different regimes (non-thermal, thermal and saturation) are identified and explained from the model and experimental results. A connection between ablation depth and simulated reached temperature is established. Further studies as micro-Raman analyses on the irradiated area and the dependence of damaged area on the repetition rate are being performed.
Colour-coded nanoscale calibration and optical quantification of axial fluorophore position
Authors: Olevsko-Arad Ilya , Feldberg Moshe , Oheim Martin , Salomon Adi
Published: October 2023

Total internal reflection fluorescence (TIRF) has come of age, but a reliable and easy-to-use tool for calibrating evanescent-wave penetration depths is missing. We provide a test-sample for TIRF and other axial super-resolution microscopies for emitter axial calibration. Our originality is that nanometer(nm) distances along the microscope’s optical axis are color-encoded in the form of a multi-layered multi-colored transparent sandwich. Emitter layers are excited by the same laser but they emit in different colors. Layers are deposited in a controlled manner onto a glass substrate and protected with a non-fluorescent polymer. Decoding the penetration depth of the exciting evanescent field, by spectrally unmixing of multi-colored samples is presented as well. Our slide can serve as a test sample for quantifying TIRF, but also as an axial ruler for nm-axial distance measurements in single-molecule localization microscopies, supercritical-angle fluorescence, and related super-resolution.
Soft glass based specialty optical fibers and their applications - INVITED
Authors: Ohishi Yasutake , Suzuki Takenobu
Published: October 2023

This paper describes a prospect for broadband mid-infrared (mid-IR) highly coherent supercontinuum generation. Tellurite and chalcogenide glass with high transparency up to the mid-IR range are used as fiber materials. We successfully develop all-solid hybrid microstructured optical fibers made of tellurite and chalcogenide glass to control chromatic dispersion and demonstrate that highly nonlinear soft glass microstructured optical fibers are promising media for broadband mid-IR highly coherent supercontinuum generation.
NV nanodiamond doped fiber for magnetic field mapping
Authors: Filipkowski Adam , Mrózek Mariusz , Stępniewski Grzegorz , Ficek Mateusz , Pysz Dariusz , Gawlik Wojciech , Buczyński Ryszard , Wojciechowski Adam , Klimczak Mariusz
Published: October 2023

The advances in fluorescent diamond-based magnetic field sensors have led this technology into the field of fiber optics. Recently, devices employing diamond nanobeams or diamond chips embedded on an optical fiber tip enabled achieving fT-level sensitivities. Nevertheless, these demonstrations were still confined to operation over localized magnetic field sources. A new approach of volumetric incorporation of nanodiamonds into the optical fiber core enables optical fibers sensitive to magnetic field at any point along the fiber length. We show that information on the perturbed spin state of a diamond nitrogen-vacancy color center can be transmitted over a macroscopic length in an optical fiber, in presence of noise from large concentration of the color centers along the fiber. This is exploited in optical readout at the fiber output not only of the magnetic field value, but also spatially variable information on the field, which enables the localization of its source.
Refractive index profiling of multimode specialty optical fibers by absorption contrast X-ray computed microtomography
Authors: Ferraro Mario , Crocco Maria C. , Mangini Fabio , Filosa Raffaele , Solano Andrea , Agostino Raffaele G. , Barberi Riccardo C. , Couderc Vincent , Klimczak Mariusz , Filipkowski Adam , Buczynski Ryszard , Wabnitz Stefan , Formoso Vincenzo
Published: October 2023

We report on successful refractive index profiling of commercially available step-index and in-house made graded-index multimode specialty optical fibers by means of X-ray computed microtomography. Our results demonstrate that the latter is an advantageous technique for characterizing large core optical fibers, which allows for retrieving information about the refractive index at optical frequencies by exploiting the absorption coefficient of X-rays.
4D optical fibers thermally drawn from shape-memory polymers
Authors: Strutynski Clément , Evrard Marianne , Désévédavy Frédéric , Gadret Grégory , Brachais Claire-Hélène , Kibler Bertrand , Smektala Frédéric
Published: October 2023

Adaptative objects based on shape-memory materials are expected to significantly impact numerous technological sectors including optics and photonics. In this work, we demonstrate the manufacturing of shape-memory optical fibers from the thermal stretching of additively manufactured preforms. First, we show how standard commercially-available thermoplastics can be used to produce long continuously-structured microfilaments with shape-memory abilities. Shape recovery as well as programmability performances of such elongated objects are assessed. Next, we open the way for light-guiding multicomponent fiber architectures that are able to switch from temporary configurations back to user-defined programmed shapes. We strongly expect that such actuatable fibers with light-guiding abilities will trigger exciting progress of unprecedented smart devices in the areas of photonics, electronics, or robotics.
Passive Q-switched Dy:ZBLAN fibre laser at 3.1 µm
Authors: Pisani Fedele , Tang Pinghua , Coluccelli Nicola , Laporta Paolo , Galzerano Gianluca
Published: October 2023

The passive Q-switching performance of an in-band pumped Dy-doped fluorozirconate fibre laser emitting around 3.1 µm is investigated. Passively Q-switched laser operation is demonstrated employing semi-conductor saturable absorber mirrors. Stable operation is achieved, with a minimum pulse duration of 464 ns, a highest repetition frequency of 210 kHz and peak pulse powers up to 3 W.
Mid-infrared supercontinuum source and evanescent wave spectroscopy based on multiple tapered sections of a singleoptical chalcogenide glass rod
Authors: Bailleul Damien , Serrano Esteban , Le Coq David , Boussard-Plédel Catherine , Désévédavy Frédéric , Smektala Frédéric , Kibler Bertrand
Published: October 2023

Mid-infrared supercontinuum sources are particularly important for identifying and characterizing molecules and materials through spectroscopy, thus enabling key applications. We here demonstrate the possibility of combining both mid-IR supercontinuum generation and evanescent wave spectroscopy in a single chalcogenide fiber device by means of heat-and-draw processes to manage linear and nonlinear wave-guiding properties.
Advances in machine learning for large-scale manufacturing of photonic circuits
Authors: Yadav Ksenia , Bidnyk Serge , Balakrishnan Ashok
Published: October 2023

Machine learning has opened a new realm of possibilities in photonic circuit design and manufacturing. First, we describe our approach of using deep learning to optimize the multi-dimensional parameter space for hundreds of optical chips on a mask, resulting in homogeneity of performance in high volume applications. Second, we present our approach of using a support vector machine to predict the performance of optical devices by wafer probing. This approach eliminates the expensive and labour-intensive process of optical chip testing, and allows unprecedented control over the fabrication process, including in-situ monitoring of wafer fabrication and real-time process adjustments. The combination of these two approaches paves the way for accelerated adoption of photonics in high volume applications.
Time-domain image processing using photonic reservoir computing
Authors: Sunada Satoshi , Yamaguchi Tomoya
Published: October 2023

Photonic computing has attracted much attention due to its great potential to accelerate artificial neural network operations. However, the processing of a large amount of data, such as image data, basically requires large-scale photonic circuits and is still challenging due to its low scalability of the photonic integration. Here, we propose a scalable image processing approach, which uses a temporal degree of freedom of photons. In the proposed approach, the spatial information of a target object is compressively transformed to a time-domain signal using a gigahertz-rate random pattern projection technique. The time-domain signal is optically acquired at a single-input channel and processed with a microcavity-based photonic reservoir computer. We experimentally demonstrate that this photonic approach is capable of image recognition at gigahertz rates.
Study of the C-band dynamical response of an injection locked LA-EEL for fully integrated telecommunication data processing
Authors: Lance Romain , Skalli Anas , Porte Xavier , Brunner Daniel
Published: October 2023

A high-performance photonic reservoir, which utilizes the injection locking effect in a highly multimodal semiconductor laser, has been developed. This innovative design allows for fully parallel and high-bandwidth operation. The output of this system is projected in space and imaged onto a digital micromirror device, which provides a readout and facilitates the hardware integration of programmable output weights. By using a highly multimodal semiconductor laser, the injection locking effect enables a large number of modes to be simultaneously locked to the injected signal, resulting in high dimensionality of the reservoir, reducing the computational time and complexity. The use of a digital micromirror device provides a flexible readout, allowing the output to be programmed to suit a range of applications. The hardware integration of programmable output weights enables the system to be optimized for specific tasks, improving performance and reducing power consumption.
Experimental Investigation of Time-Stretch-Based Reservoir Computing with an Optical Input Mask
Authors: Yue Yuanli , Liu Shouju , Xu Weichao , Wang Chao
Published: October 2023

In this paper, we experimentally demonstrated a novel all-optical reservoir computer with an all optical input mask. The combination of the binary random masks and the time-stretched ultrashort pulses has increased the system’s classification performance. Compared with the traditional digital masks, this method shows superior classification performance in spoken-digit classification tasks and eliminates the need for high-speed modulation for digital masks.
Image classification with a fully connected opto-electronic neural network
Authors: Song Alexander , Murty Kottapalli Sai Nikhilesh , Fischer Peer
Published: October 2023

Optical approaches have made great strides enabling high-speed, scalable computing necessary for modern deep learning and AI applications. In this study, we introduce a multilayer optoelectronic computing framework that alternates between optical and optoelectronic layers to implement matrix-vector multiplications and rectified linear functions, respectively. The system is designed to be real-time and parallelized, utilizing arrays of light emitters and detectors connected with independent analog electronics. We experimentally demonstrate the operation of our system and compare its performance to a single-layer analog through simulations.
Raman signal extraction from BCARS intensity measurements using deep learning with a prior excitation profile
Authors: Muddiman Ryan , O’Dwyer Kevin , Camp Charles H. , Hennelly Bryan
Published: October 2023

Broadband Coherent anti-Stokes Raman Scattering (BCARS) microscopy is a useful technique for chemical analysis and allows the full vibrational fingerprint spectrum of a specimen to be obtained in millisec-onds. A major drawback to this technique is the presence of the non-resonant background response producing interference which prevents classical spectral analysis of the sample. Using a convolutional autoencoder and measurements of the laser characteristics, we have shown that it is possible to remove this background with-out requiring supervision, as is typically required for conventional removal methods. This approach therefore simplifies the analysis of hyperspectral images obtained with BCARS.
Graphene/4H-SiC Schottky photodetector operating in the visible spectrum range
Authors: Mallemace Elisa D. , Crisci Teresa , Gioffrè Mariano , Medugno Mario , Della Corte Francesco G. , Rao Sandro , Casalino Maurizio
Published: October 2023

In this work, we present the first experimental results on a Schottky photodetector based on Silicon Carbide (SiC) and Graphene (Gr) designed to operate in the visible spectral range. While SiC has been extensively investigated for various applications in the ultraviolet domain, there are only a few works in the visible range, where SiC exhibits negligible optical absorption. To overcome such intrinsic limit of SiC, we exploit the properties of a single layer of Gr to enhance, significantly, the photodetection performance of the device operating, in our experiments, at the wavelength of λ=633 nm. From the current-voltage (I-V) characteristics, a series resistance of 3.7 kΩ, an ideality factor of 8.4, and the zero-bias Schottky barrier height of 0.755 eV have been calculated. Finally, the internal responsivity, as function of the reverse bias applied to the device, has been measured demonstrating a maximum value exceeding 1 mA/W at -5V.
Update Leitlinie Psoriasisarthritis
Authors: Sewerin Philipp , Kiefer David , Baraliakos Xenofon
Published: October 2023

Für die Psoriasisarthritis (PsA) stehen heute seitens der European Alliance of Associations for Rheumatology (EULAR) und der Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2 internationale Leitlinien zur Verfügung, die evidenzbasiert Therapievorschläge für die heterogene Gruppe der PsA-Patient*innen vorschlagen. Hierbei werden in beiden Leitlinien die unterschiedlichen Domänen, wie die periphere Arthritis, die axiale Beteiligung oder das Ausmaß der Hautbeteiligung, adressiert. So finden wir in den EULAR-Leitlinien unterschiedliche Empfehlungen für primär peripher arthritische, axiale oder enthesiale Verlaufsformen, wohingegen die Hautbeteiligung selbst therapeutisch nicht fokussiert wird. Bei den GRAPPA-Empfehlungen werden rein domänenspezifische Therapievorschläge angeboten, welche somit noch spezifischer und individueller genutzt werden können, allerdings im Einzelfall ggf. einen weniger konkreten Therapievorschlag liefern können. Neben der Therapie selbst ist das Messen des Therapieerfolges und das Festlegen eines klaren Therapieziels heute von großer Bedeutung, was nur mit validierten Messinstrumenten möglich ist, welche ebenfalls angesprochen werden sollen.
Sustained Effect of Clinical Decision Support for Heart Failure: A Natural Experiment Using Implementation Science
Authors: Trinkley Katy E. , Wright Garth , Allen Larry A. , Bennett Tellen D. , Glasgow Russell E. , Hale Gary , Heckman Simeon , Huebschmann Amy G. , Kahn Michael G. , Kao David P. , Lin Chen-Tan , Malone Daniel C. , Matlock Daniel D. , Wells Lauren , Wysocki Vincent , Zhang Shelley , Suresh Krithika
Published: October 2023

Objectives In a randomized controlled trial, we found that applying implementation science (IS) methods and best practices in clinical decision support (CDS) design to create a locally customized, “enhanced” CDS significantly improved evidence-based prescribing of β blockers (BB) for heart failure compared with an unmodified commercially available CDS. At trial conclusion, the enhanced CDS was expanded to all sites. The purpose of this study was to evaluate the real-world sustained effect of the enhanced CDS compared with the commercial CDS.

Methods In this natural experiment of 28 primary care clinics, we compared clinics exposed to the commercial CDS (preperiod) to clinics exposed to the enhanced CDS (both periods). The primary effectiveness outcome was the proportion of alerts resulting in a BB prescription. Secondary outcomes included patient reach and clinician adoption (dismissals).

Results There were 367 alerts for 183 unique patients and 171 unique clinicians (pre: March 2019–August 2019; post: October 2019–March 2020). The enhanced CDS increased prescribing by 26.1% compared with the commercial (95% confidence interval [CI]: 17.0–35.1%), which is consistent with the 24% increase in the previous study. The odds of adopting the enhanced CDS was 81% compared with 29% with the commercial (odds ratio: 4.17, 95% CI: 1.96–8.85). The enhanced CDS adoption and effectiveness rates were 62 and 14% in the preperiod and 92 and 10% in the postperiod.

Conclusion Applying IS methods with CDS best practices was associated with improved and sustained clinician adoption and effectiveness compared with a commercially available CDS tool.
Vorwurf der Wettbewerbsverzerrung: Berliner Kliniken verklagen das Land
Authors: Eilers Susann
Published: October 2023

Ein Bündnis von Berliner Kliniken hat Klage eingereicht. Die Häuser wehren sich gegen eine millionenschwere Bevorzugung des landeseigenen Klinikkonzerns Vivantes. Im Raum steht die verdeckte Dauerfinanzierung von Verlusten durch die Steuerzahler.
Kalter Strukturwandel: Insolvenzen beschäftigen die Kliniken
Authors: Hollmig Luisa-Maria
Published: October 2023

70 Prozent der Kliniken sehen ihre Existenz kurz- oder mittelfristig gefährdet. Das ist das Ergebnis einer Blitzumfrage des Deutschen Krankenhausinstituts (DKI) im Auftrag der Deutschen Krankenhausgesellschaft (DKG). Fast kein Krankenhaus kann seine Ausgaben noch aus den laufenden Einnahmen decken. Wie drastisch die Lage ist, zeigte sich in den vergangenen Wochen.
Rechtskolumne: Transplantationsskandal – die Krankenkasse muss zahlen
Authors: Rybak Christian
Published: October 2023

Trotz Manipulation und der Weitergabe falscher Angaben an Eurotransplant hat das Universitätsklinikum einen Anspruch auf Vergütung für medizinisch notwendige Behandlungen. Dies entschied das Bundesozialgericht (BSG) im Göttinger Transplantationsskandal.
Mitarbeiterbindung: Per Job Journey durch die BG-Galaxis
Authors: Hollmig Luisa-Maria
Published: October 2023

Mit einem neuen Stellenkonzept schickt das BG Universitätsklinikum Bergmannsheil neue Mitarbeitende auf eine „Job Journey“. Das Ziel: Nicht nur die richtige Station, sondern auch das ideale Team finden. Gut ein halbes Jahr nach Projektstart ist es Zeit für eine Zwischenbilanz – und die ist positiv.
In Search of the Perfect Thrombosis and Bleeding-Associated Cancer Scale
Authors: Wojtukiewicz Marek Z. , Tesarova Petra , Karetová Debora , Windyga Jerzy
Published: October 2023

Thrombosis and bleeding are commonly observed in cancer patients, and their management is crucial for positive patient outcomes. A comprehensive, prophylactic, and therapeutic management of venous thrombosis should focus on identifying the patients who would benefit most from treatment to reduce mortality and minimize the risk of thrombosis recurrence without significantly increasing the risk of bleeding. Existing cancer scales provide valuable information for assessing the overall burden of cancer and guiding treatment decisions, but their ability to predict thrombotic and bleeding events remains limited. With increasing knowledge of the pathophysiology of cancer and the availability of advanced anticancer therapies, new risk factors for cancer-associated thrombosis and bleeding are being identified. In this report, we analyze the current literature and identify new risk factors for venous thrombosis and bleeding which are not included in routinely used risk scores. While some existing cancer scales partially capture the risk of thrombosis and bleeding, there is a need for more specific and accurate scales tailored to these complications. The development of such scales could improve risk stratification, aid in treatment selection, and enhance patient care. Therefore, further research and development of novel cancer scales focused on thrombosis and bleeding are warranted to optimize patient management and outcomes.
Optothermal crystallization of hard spheres in an effective bidimensional geometry
Authors: Ruzzi Vincenzo , Baglioni Jacopo , Piazza Roberto
Published: October 2023

Using colloids effectively confined in two dimensions by a cell with a thickness comparable to the particle size, we investigate the nucleation and growth of crystallites induced by locally heating the solvent with a near-infrared laser beam. The particles, which are “thermophilic,” move towards the laser spot solely because of thermophoresis with no convection effects, forming dense clusters whose structure is monitored using two order parameters that gauge the local density and the orientational ordering. We find that ordering takes place when the cluster reaches an average surface density that is still below the upper equilibrium limit for the fluid phase of hard disks, meaning that we do not detect any sign of a proper “two-stage” nucleation from a glass or a polymorphic crystal structure. The crystal obtained at late growth stage displays a remarkable uniformity with a negligible amount of defects, arguably because the incoming particles diffuse, bounce, and displace other particles before settling at the crystal interface. This “fluidization” of the outer crystal edge may resemble the surface enhanced mobility giving rise to ultra-stable glasses by physical vapor deposition.
Global dynamics, thermodynamics and non-equilibrium origin of bifurcations for single neuron dynamics
Authors: Wang Xiaochen , Wu Yuxuan , Xu Liufang , Wang Jin
Published: October 2023

The understanding of neural excitability and oscillations in single neuron dynamics remains incomplete in terms of global stabilities and the underlying mechanisms for phase formation and associated phase transitions. In this study, we investigate the mechanism of single neuron excitability and spontaneous oscillations by analyzing the potential landscape and curl flux. The topological features of the landscape play a crucial role in assessing the stability of resting states and the robustness/coherence of oscillations. We analyze the excitation characteristics in Class I and Class II neurons and establish their relation to biological function. Our findings reveal that the average curl flux and associated entropy production exhibit significant changes near bifurcation or phase transition points. Moreover, the curl flux and entropy production offer insights into the dynamical and thermodynamical origins of nonequilibrium phase transitions and exhibit distinct behaviors in Class I and Class II neurons. Additionally, we quantify time irreversibility through the difference in cross-correlation functions in both forward and backward time, providing potential indicators for the emergence of nonequilibrium phase transitions in single neurons.
Design and experimental study of electromagnetic clutch-type variable pre-pressure ultrasonic motor
Authors: Niu Ruikun , Guo Yong , Liu Jun , Wu Guanqi , Sun Li
Published: October 2023

The traveling-wave rotary ultrasonic motor (TRUM) technique has become increasingly mature deepening of related research and development of related technology. The unique friction drive mode of a TRUM provides the advantages of a low speed, large torque, fast response, and a self-locking feature for power failure but also suffers from a relatively low efficiency. Regarding speed control, the commonly used approach of combining frequency modulation and speed regulation has provided the advantages of high precision and a wide range. Still, the load-carrying capacity of a TRUM is reduced when the driving frequency deviates from the resonant point, which is not conducive to the characteristics of low speed and large torque of the TRUM. To address this limitation, this study uses the pre-pressure and designs an electromagnetic clutch-type variable pre-pressure self-adjusting ultrasonic motor based on the TRUM-70 hollow ultrasonic motor. In addition, the force and motion analyses are conducted on the core components, and the basic parameters of the electromagnetic mechanism are calculated according to the specific design requirements. Furthermore, the Maxwell equation is used to simulate the designed magnetic circuit, and a prototype is fabricated and assembled. The feasibility of the proposed motor design is verified through experimental study, and the performance of the motor is compared with those of conventional ultrasonic motors. The experimental results show that the proposed electromagnetic clutch-type variable pre-pressure ultrasonic motor can effectively improve the output efficiency of the motor, especially when the load varies significantly.
Decoupled rocket model of a spherical shell implosion in inertial confinement fusion
Authors: Li Lulu , Xu Ruihua , Zhao Yingkui , Wen Wu
Published: October 2023

In inertial confinement fusion, the rocket model has achieved great success in describing many important effects, including the residual mass of the shell, average implosion velocity, the motion of the ablative surface, and rocket efficiency (the ratio of the kinetic energy of the shell to absorbed energy). This model uses only the implosion parameter to describe the spherical ablative implosion dynamics under the thin-shell assumption. In this paper, we introduce a decoupled rocket model using an additional parameter that extends beyond the thin-shell assumption to describe the implosion dynamics at the same time. This provides information for the theoretical design of a thick shell by optimizing two parameters rather than only one implosion parameter. To demonstrate this, we apply these two models to design single-shell targets driven by the same radiation source. Our simulations show the decoupled rocket model can get better theoretical design results in a larger parameter space.