Hybrid Integration Research Articles

High power GaSb-based superluminescent diode with cascade cavity suppression waveguide geometry and ultra-low antireflection coating

We report on a GaSb-based superluminescent diode optimized for high-power broadband operation around a wavelength of 2 μm. The high optical power was achieved by the high-quality epitaxial InGaSb/AlGaAsSb type-I quantum well gain material, which was processed into a double-pass amplification configuration. To prevent lasing at high current injection while enabling strong amplified spontaneous emission, a cascade cavity suppression waveguide geometry was designed to connect the vertical rear facet with the reflectivity-suppressed angled front facet. A Ta2O5/SiO2 ultra-low antireflection coating with a minimum reflectivity of 0.04% was applied to the front facet for further cavity suppression. This combination allowed the superluminescent diodes to demonstrate a record high single-transverse-mode output power of up to 152 mW under continuous-wave operation at room temperature, with a broad spectral band of 42 nm full width at half maximum. A 25% promotion in optical power has been realized compared to current state-of-the-art devices in this wavelength range, without sacrificing spectral bandwidth. The high-power spectral density characteristics, along with a good beam quality, are well suited for absorption spectroscopy applications and hybrid integration with silicon technology.

How to Read Out the Phonon Number Statistics via Resonance Fluorescence Spectroscopy of a Single‐Photon Emitter

AbstractIn today's development of quantum technologies a hybrid integration of phononic excitations becomes increasingly attractive. As natural quasi‐particle excitations in solid state systems, phonons couple to virtually any other excitation and therefore constitute a useful interaction channel between different building blocks in hybrid quantum systems. This work explores how the efficient light‐scattering properties of a single‐photon emitter and the appearance of characteristic sidebands in resonance fluorescence spectra, when interfaced with an arbitrary phonon quantum state, can be utilized for acousto‐optical transduction. Within reasonable approximations, an analytical description for the optical spectra in the low excitation limit is developed which can be used to read the number statistics of the initial phonon state from a given spectrum. It is shown that the readout is faulty in situations where relevant resonant transitions are forbidden due to vanishing Franck–Condon factors, especially when considering spectra with a noisy background. Two possible solutions to this problem are presented: (A) changing the detuning of the laser relative to the single‐photon emitter which modifies the relevant resonant transitions, or (B) increasing dissipation of the single‐photon emitter to promote off‐resonant transitions.

Microfabrication Process Development for a Polymer-Based Lab-on-Chip Concept Applied in Attenuated Total Reflection Fourier Transform Infrared Spectroelectrochemistry.

Micro electro-mechanical systems (MEMS) combining sensing and microfluidics functionalities, as are common in Lab-on-Chip (LoC) devices, are increasingly based on polymers. Benefits of polymers include tunable material properties, the possibility of surface functionalization, compatibility with many micro and nano patterning techniques, and optical transparency. Often, additional materials, such as metals, ceramics, or silicon, are needed for functional or auxiliary purposes, e.g., as electrodes. Hybrid patterning and integration of material composites require an increasing range of fabrication approaches, which must often be newly developed or at least adapted and optimized. Here, a microfabrication process concept is developed that allows one to implement attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and electrochemistry on an LoC device. It is designed to spatially resolve chemical sensitivity and selectivity, which are instrumental for the detection of chemical distributions, e.g., during on-flow chemical and biological reaction chemistry. The processing sequence involves (i) direct-write and soft-contact UV lithography in SUEX dry resist and replication in polydimethylsiloxane (PDMS) elastomers as the fluidic structure; (ii) surface functionalization of PDMS with oxygen plasma, 3-aminopropyl-triethoxysilane (APTES), and a UV-curable glue (NOA 73) for bonding the fluidic structure to the substrate; (iii) double-sided patterning of silicon nitride-coated silicon wafers serving as the ATR-FTIR-active internal reflection element (IRE) on one side and the electrode-covered substrate for microfluidics on the back side with lift-off and sputter-based patterning of gold electrodes; and (iv) a custom-designed active vacuum positioning and alignment setup. Fluidic channels of 100 μm height and 600 μm width in 5 mm thick PDMS were fabricated on 2" and 4" demonstrators. Electrochemistry on-chip functionality was demonstrated by cyclic voltammetry (CV) of redox reactions involving iron cyanides in different oxidation states. Further, ATR-FTIR measurements of laminar co-flows of H2O and D2O demonstrated the chemical mapping capabilities of the modular fabrication concept of the LoC devices.

Dialogic negotiations of children’s narratives in classroom workshops

Abstract This article investigates how dialogic negotiations contribute to the enhancement of pupils’ epistemic authority. The analysis was based on two interactions collected in a primary school and a higher secondary school in Italy, as part of a European research project promoting dialogue-based activities. The aim of the research was to investigate children’s agency and participation in changing their social and cultural conditions of hybrid integration. Their participation was promoted in different ways to facilitate dialogue, which enhanced dialogic negotiations and narrative interlacement. The analysis demonstrates that, through dialogic negotiations, children and adults shape the meanings of children’s personal stories together and create a network of interlaced narratives. Both these conditions impact on children’s participation in knowledge production and identity construction.

Stabilized low-order finite-element formulation for static and dynamic simulation of saturated soils based on a hybrid integration scheme

This paper presents a stabilized linear finite-element formulation for three-dimensional (3D) elastoplastic static and dynamic coupled analyses of the soil skeleton and pore fluid. The proposed hybrid integration scheme can improve the speed and accuracy of the simulation while ensuring stability. The one-point reduced integration with hourglass stabilization and anti-locking strategy was used for the stress–strain calculation, while the full integration was adopted for analyzing other parts, such as the fluid phase. A robust pore-pressure stabilization method was derived to solve the oscillation problem for equal-order linear interpolation in the incompressible-undrained limit. In the field of large-scale 3D elastoplastic coupled solid–fluid simulations, academia has been committed to finding a method that considers the speed, stability, and accuracy of the simulation. The proposed finite-element formulation provides an effective solution for this purpose.

Dynamics analysis for DC transformers integration in hybrid AC‐DC power distribution networks

AbstractIn AC/DC power distributions networks, power converters are interfacing buses to ensure DC voltage regulation and power distribution. Active front ends are used between AC and DC buses and two typical control schemes that can be implemented are voltage regulation or power regulation. On the DC side, open‐loop operated DC transformers could be used between two DC buses to provide voltage adaptation, isolation and natural power flow. In this context, power flows and DC bus voltages in the power distribution network are dependent on the combined operation of the active front ends and the DC transformer. Mainly studied from a stability perspective, this interdependency between active front ends and DC transformers has lacked investigations in terms of dynamics. Fast dynamics is nevertheless important to operate optimally a network. In this paper, the assessment of the dynamic performance for distribution systems with DC transformers is performed for different mixes of voltage regulating and power regulating active front ends. The influence of DC line length and DC transformer power reversal method on the system is further investigated. A model of the system is proposed, validated experimentally and can be used to aid system level design and analysis of future DC systems.

Fiber-coupled plug-and-play heralded single photon source based on Ti:LiNbO3 and polymer technology.

A reliable, but cost-effective generation of single-photon states is key for practical quantum communication systems. For real-world deployment, waveguide sources offer optimum compatibility with fiber networks and can be embedded in hybrid integrated modules. Here, we present what we believe to be the first chip-size fully integrated fiber-coupled heralded single photon source (HSPS) module based on a hybrid integration of a nonlinear lithium niobate waveguide into a polymer board. Photon pairs at 810 nm (signal) and 1550 nm (idler) are generated via parametric down-conversion pumped at 532 nm in the LiNbO3 waveguide. The pairs are split in the polymer board and routed to separate output ports. The module has a size of (2 × 1) cm2 and is fully fiber-coupled with one pump input fiber and two output fibers. We measure a heralded second-order correlation function of g h(2)=0.05 with a heralding efficiency of η h=3.5% at low pump powers.

Integration of hybrid and self-correction method improves the quality of long-read sequencing data.

Third-generation sequencing (TGS) technologies have revolutionized genome science in the past decade. However, the long-read data produced by TGS platforms suffer from a much higher error rate than that of the previous technologies, thus complicating the downstream analysis. Several error correction tools for long-read data have been developed; these tools can be categorized into hybrid and self-correction tools. So far, these two types of tools are separately investigated, and their interplay remains understudied. Here, we integrate hybrid and self-correction methods for high-quality error correction. Our procedure leverages the inter-similarity between long-read data and high-accuracy information from short reads. We compare the performance of our method and state-of-the-art error correction tools on Escherichia coli and Arabidopsis thaliana datasets. The result shows that the integration approach outperformed the existing error correction methods and holds promise for improving the quality of downstream analyses in genomic research.

Near‐Infrared InGaAs Intelligent Spectral Sensor by 3D Heterogeneous Hybrid Integration

The applications of near‐infrared spectroscopy (NIRS) are limited due to the bulky size, low integration, and poor intelligence in edge computing of traditional spectrometers. In this work, the authors develop an on‐chip InGaAs intelligent spectral sensor, which consists of a linear variable filter for wavelength selection, a linear focal plane array as detector and a chip processor for neural‐network inferring, based on an advanced 3D heterogeneous hybrid‐integration. More than 200 spectral channels with a spectral resolution of 1.25% central wavelength are acquired in a wide waveband from 900 to 1700 nm. Immediate results are provided onsite for users, especially applicable to nonspecialists, owing to the embedded algorithmic model in‐sensor. As a proof of applications, the authors experimentally detect adulterating green tea and achieve a real‐time identification with accuracy better than 90%. This spectral sensor with edge‐artificial‐intelligence breaks the dependence on external algorithms and paves the way for NIRS into miniaturization, integration, and intelligence, which brings more possibilities in incorporating with the consumer devices and the Internet of Things.

Archaeological Predictive Modeling Using Machine Learning and Statistical Methods for Japan and China

Archaeological predictive modeling (APM) is an essential method for quantitatively assessing the probability of archaeological sites present in a region. It is a necessary tool for archaeological research and cultural heritage management. In particular, the predictive modeling process could help us understand the relationship between past human civilizations and the natural environment; moreover, a better understanding of the mechanisms of the human–land relationship can provide new ideas for sustainable development. This study aims to investigate the impact of topographic and hydrological factors on archaeological sites in the Japanese archipelago and Shaanxi Province, China and proposes a hybrid integration approach for APM. This approach employed a conditional attention mechanism (AM) using deep learning and a frequency ratio (FR) model, in addition to a separate FR model and the widely-used machine learning MaxEnt method. The models’ outcomes were cross-checked using the four-fold cross-validation method, and the models’ performances were compared using the area under the receiver operating characteristic curve (AUC) and Kvamme’s Gain. The results showed that in both study areas, the AM_FR model exhibited the most satisfactory performances.

To study the effect of ER flux with buffer on the neuronal calcium.

Calcium signaling is decisive for cellular functions. This calcium random walk stipulates neuronal functions. Calcium concentration could provoke gene transcription, apoptosis, neuronal plasticity, etc. A malformation in calcium could change the neuron's intracellular behavior. Calcium concentration balancing is a complex cellular mechanism. This occurrence can be handled with the Caputo fractional reaction-diffusion equation. In this mathematical modeling, we have included the STIM-Orai mechanism and Endoplasmic Reticulum (ER) flux, Inositol Triphosphate Receptor (IPR), SERCA, plasma membrane flux, voltage-gated calcium entry, and different buffer interactions. A hybrid integral transform and Green's function approach were taken to solve the initial boundary problem. A closed-form solution of a Mittag-Leffler family function plotted using MATLAB software. Different parameters impact changes in the spatiotemporal behavior of the calcium concentration. Specific roles of organelles involved in Alzheimer's disease-affected neurons are computed. Ethylene glycol tetraacetic acid (EGTA), 1,2-bis(o-aminophenoxy)ethane N,N,N,N-tetraacetic acid (BAPTA), and S100B protein effects are also observed. In all simulations, we can say S100B and the STIM-Orai effect cannot be neglected. This model lights up the different approaches for calcium signaling pathway simulation. As a consequence, we determine that a generalized reaction-diffusion approach is a better fit realistic model.

11‐2: A 9 kfps 1411 PPI GaN‐based µLED Display CMOS Backplane

The revolution of the GaN‐on‐Si hybrid integration has redefined microdisplay as a point‐light source for scientific, communication and visualization applications, thanks to their superior capabilities in terms of resolution, brightness and switching speed. In this work, we present a CMOS (Complementary Metal‐Oxide Semiconductor) backplane able to exploit the GaN microarrays capabilities, producing high‐speed patterns (up to 9.15 kfps) at high optical intensities (up to 120 uA per pixel and 16 grey levels) at an unprecedented resolution of 1411 PPI (512×512 pixel with 18um pitch). In addition, the backplane can be operated in pulsed mode, allowing the entire array to be toggled between the stored frame and off state at 1 MHz. Its unique characteristics expand the range of possible applications, from fluorescence‐based performance assays to the manufacturing of DNA chips.

Dependable STT-MRAM With Emerging Approximation and Speculation Paradigms

Spin-Transfer-Torque (STT) MRAM is configured with high access speed, readily hybrid integration and guaranteed endurance/retention, which becomes one of the most promising candidates for next generation memory. However, the major challenge of STT-MRAM is its high switching energy consumption, accompanied with unreliable writing operation. This work exploits two emerging design paradigms entitled approximation and speculation MRAM. A novel design scheme with timing speculation and approximate storage is proposed to improve energy efficiency in MRAM write operation by reducing write time. Simulation results show that latency and energy loss in entire write operation can be significantly reduced. The proposed technique obtains 84%/57.4% in the symmetric and unidirectional writing operations. Meanwhile, timing speculative method improves the failure/reliability in writing by re-write strategy. Related MRAM macro specification is applied to image processing, which obtains 10% (58.8%-67.2%) of the improvement of precision in image and higher image quality is obtained under the same accuracy rate.

Energy, economic, and environmental assessment of the integration of phase change materials and hybrid concentrated photovoltaic thermal collectors for reduced energy consumption of a school sports center

In this study, dynamic simulations of an existing school sports building located in a hot semi-arid steppe climate (BSh) were carried out to evaluate the energy, economic, and environmental performance of an inorganic phase change material (PCM) and a low-concentration photovoltaic thermal (LCPV/T) hybrid collector. For this purpose, transient thermal simulations incorporating software elements were used to model the passive and active technologies. Different scenarios applied in the building -the integration of PCM into the roof (C1), the use of the LCPV/T collector system (C2), and the simultaneous use of these technologies (C3)- were established, and their energy savings, economic feasibility, and environmental impact were obtained. The combination of the PCM with melting point of 23 °C and hybrid collectors reduced the annual building electricity up to 5.8%. C1 is the best option if the cost of the PCM23 decreases to 13% of the original price, with a SPB and IRR of 3.7 years and 27%, respectively. C3 is economically feasible if the collector price is also reduced to 80%, achieving a SPB and IRR of 12.1 years and 6.6%. Finally, the greenhouse gases prevented emissions of up to 162, 138, and 24 tonCO2e/year are for C3, C2, and C1, respectively.

Boosting radical innovativeness through start‐up acquisitions: the role of decision autonomy and structural integration

Since start‐ups often own cutting‐edge technology and knowledge, acquiring a start‐up can provide buyers with a unique opportunity to boost their radical innovativeness. As a result, start‐up acquisitions have increasingly gained importance. Acquirers, however, face difficult decisions on target autonomy and integration, which often constitute a dilemma. We analyzed survey data from 118 M&A and integration managers in charge of corporate start‐up acquisitions. Our results show that a start‐up's decision‐making autonomy supports acquirer's radical innovativeness. The structural integration of the target reinforces the positive effect of decision autonomy. Our work with the focus on post‐merger integration and the start‐up context contributes to M&A literature in several ways. We uncover a hybrid integration approach, showing that a combination of high target decision autonomy and the full absorption (i.e., structural integration) of the start‐up by the acquiring organization is most beneficial for acquirer's radical innovativeness.

Hybrid-integrated wideband tunable optoelectronic oscillator.

As a photonic-based microwave signal generation method, the optoelectronic oscillator (OEO) has the potential of meeting the increasing demand of practical applications for high frequency, broadband tunability and ultra-low phase noise. However, conventional OEO systems implemented with discrete optoelectronic devices have a bulky size and low reliability, which extremely limits their practical applications. In this paper, a hybrid-integrated wideband tunable OEO with low phase noise is proposed and experimentally demonstrated. The proposed hybrid integrated OEO achieves a high integration level by first integrating a laser chip with a silicon photonic chip, and then connecting the silicon photonic chip with electronic chips through wire-bonding to microstrip lines. A compact fiber ring and an yttrium iron garnet filter are also adopted for high-Q factor and frequency tuning, respectively. The integrated OEO exhibits a low phase noise of -128.04 dBc/Hz @ 10 kHz for an oscillation frequency of 10 GHz. A wideband tuning range from 3 GHz to 18 GHz is also obtained, covering the entire C, X, and Ku bands. Our work demonstrates an effective way to achieve compact high-performance OEO based on hybrid integration, and has great potential in a wide range of applications such as modern radar, wireless communication, and electronic warfare systems.

Highly stretchable strain sensors based on Marangoni self-assemblies of graphene and its hybrids with other 2D materials

Graphene and other two-dimensional materials (2DMs) have been shown to be promising candidates for the development of flexible and highly-sensitive strain sensors. However, the successful implementation of 2DMs in practical applications is slowed down by complex processing and still low sensitivity. Here, we report on a novel development of strain sensors based on Marangoni self-assemblies of graphene and of its hybrids with other 2DMs that can both withstand very large deformation and exhibit highly sensitive piezoresistive behaviour. By exploiting the Marangoni effect, reference films of self-assembled reduced graphene oxide (RGO) are first optimized, and the electromechanical behaviour has been assessed after deposition onto different elastomers demonstrating the potential of producing strain sensors suitable for different fields of application. Hybrid networks have been then prepared by adding hexagonal boron nitride (hBN) and fluorinated graphene (FGr) to the RGO dispersion. The hybrid integration of 2D materials is demonstrated to become a potential solution to increase substantially the sensitivity of the produced resistive strain sensors without compromising the mechanical integrity of the film. In fact, for large quasi-static deformations, a range of gauge factor values up to 2000 were demonstrated, while retaining a stable performance under cyclic deformations.

Toward Practical Optical Phased Arrays through Grating Antenna Engineering

In recent years, using silicon-based waveguide grating antennas in optical phased array has become a research focus. To date, this technique has not been widely implemented in practical applications. In this paper, the basic principle of a waveguide grating antenna is described, and the researches on effective length, uniform emission and the directionality of diffraction are summarized. Through analysis, it is found that there is a trend to prepare grating antennas by using a SiN/Si hybrid integrated platform. A novel design of grating antenna using the hybrid integration technique is proposed. It is convenient to match with the antenna front-end components on the structural level and is more practical.

Optoelectronic Metasurface for Free-Space Optical–Microwave Interactions

Photon-electron interactions are essential for many areas such as energy conversion, signal processing, and emerging quantum science. However, the current demonstrations are typically targeted to fiber and on-chip applications and lack of study in wave space. Here, we introduce a concept of optoelectronic metasurface that is capable of realizing direct and efficient optical-microwave interactions in free space. The optoelectronic metasurface is realized via a hybrid integration of microwave resonant meta-structures with a photoresponsive material. As a proof of concept, we construct an ultrathin optoelectronic metasurface using photodiodes that is bias free, which is modeled and analyzed theoretically by using the light-driven electronic excitation principle and microwave network theory. The incident laser and microwave from the free space will interact with the photodiode-based metasurface simultaneously and generate strong laser-microwave coupling, where the phase of output microwave depends on the input laser intensity. We experimentally verify that the reflected microwave phase of the optoelectronic metasurface decreases as the incident laser power becomes large, providing a distinct strategy to control the vector fields by the power intensity. Our results offer fundamentally new understanding of the metasurface capabilities and the wave-matter interactions in hybrid materials.

On-skin biosensors for noninvasive monitoring of postoperative free flaps and replanted digits

Severe soft tissue defects and amputated digits are clinically common injuries. Primary treatments include surgical free flap transfer and digit replantation, but these can fail because of vascular compromise. Postoperative monitoring is therefore crucial for timely detection of vessel obstruction and survival of replanted digits and free flaps. However, current postoperative clinical monitoring methods are labor intensive and highly dependent on the experience of nurses and surgeons. Here, we developed on-skin biosensors for noninvasive and wireless postoperative monitoring based on pulse oximetry. The on-skin biosensor was made of polydimethylsiloxane with gradient cross-linking to create a self-adhesive and mechanically robust substrate that interfaces with skin. The substrate was shown to exhibit appropriate adhesion on one side for both high-fidelity measurements of the sensor and low risk of peeling injury to delicate tissues. The other side demonstrated mechanical integrity to facilitate flexible hybrid integration of the sensor. Validation studies using a model of vascular obstruction in rats demonstrated the effectiveness of the sensor in vivo. Clinical studies indicated that the on-skin biosensor was accurate and more responsive than current clinical monitoring methods in identifying microvascular conditions. Comparisons with existing monitoring techniques, including laser Doppler flowmetry and micro-lightguide spectrophotometry, further verified the sensor's accuracy and ability to identify both arterial and venous insufficiency. These findings suggest that this on-skin biosensor may improve postoperative outcomes in free flap and replanted digit surgeries by providing sensitive and unbiased data directly from the surgical site that can be remotely monitored.