bluuebunny/crossref_metadata_2025 huggingface dataset:
Better Together! The Consumer Implications of Delivery Consolidation
Authors: Wagner Laura , Calvo Eduard , Amorim Pedro
Published: February 2023

Problem definition: Online retailers often receive customer orders comprising several products of differing origins. To fulfill these orders, retailers must ship multiple parcels from different locations and—unless they are grouped somewhere along the supply chain—these may reach the customer’s doorstep one by one. Academic/practical relevance: We conjecture here that receiving products sequentially instead of all together affects a consumer’s reaction to her purchases, possibly influencing—for good or ill—her decision to return products, as well as her overall service satisfaction. We use two-year granular data from an online fashion marketplace to test this hypothesis and characterize consumer behavioral responses to delivery consolidation and examine how it impacts supply chain stakeholders. Methodology: To achieve causal inference, we exploit the fact that the couriers used by the focal marketplace gather together certain parcels for reasons related more to the timing of their arrival than their actual customers, thereby exogenously consolidating the delivery of some orders. We construct a balanced sample of matched twin multiproduct orders that are alike in all respects except their delivery: consolidated (all parcels delivered jointly) versus otherwise (split). Results: We find that delivery consolidation benefits the marketplace and all its suppliers. By eliminating the stress associated with split deliveries, delivery consolidation pleases consumers as it leads to fewer returns and higher overall satisfaction. Managerial implications: Delivering all products in an order together, even if later, reduces the probability of a return, which improves the financial performance of the marketplace and its suppliers and reduces reverse logistics. Our results suggest that in our context, delivery speed matters less than the convenience of receiving all ordered goods in a single delivery, and we provide directions for adapting logistics strategies accordingly. Our empirical findings also imply that the return decisions of multiple products purchased at once should not be considered to be independent. Finding tractable ways of modeling this feature will be necessary in further driving retail practice through theoretical research that accounts for the behavioral implications of delivery consolidation when optimizing fulfillment decisions.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2023.1200 .
Effect of combined intervention of exercise and autologous bone marrow stromal cell transplantation on neurotrophic factors and pain-related cascades over time after sciatic nerve injury
Authors: Yu Joo-In , Cho Yeong-Hyun , Seo Tae-Beom , Kim Young-Pyo
Published: February 2023

The purpose of this study was to determine whether combined intervention of treadmill exercise and bone marrow stromal cell (BMSC) transplantation would affect the expression of neurotrophic factors in the sciatic nerve injury (SNI) and neuropathic pain-related cascades in ipsilateral lumbar 4-5 dorsal root ganglion (DRG) during the early or late stage of sciatic nerve regeneration. The rats were randomly divided into the normal control group (CONT, n= 6), sedentary group (SS, n= 24), exercise group (SE, n= 24), BMSC transplantation group (SB, n= 24), BMSC transplantation+exercise group (SBE, n= 24) 1, 2, 3, and 5 weeks after SNI. Single dose of 5× 106 harvested BMSC was injected into the injury area sing by a 30 gauge needle. Treadmill exercise was performed at a speed of 8 m/min for 30 min once a day. Tropomyosin-receptor kinase B, brain-derived neurotrophic factor and ciliary neurotrophic factor were significantly upregulated in the SE and SBE groups at 1- and 2-week postinjury than those in the CONT and SS groups, and SB and SBE groups continuously kept up proinflammatory cytokines until the late stage of regeneration. Nuclear factor kappa-light-chain-enhancer of activated B cells, interleukin and tumor necrosis factor alpha in ipsilateral DRG were progressively decreased by exercise alone application and/or BMSC transplantation at early and late stage of regeneration. Present results provide reliable information that combined intervention of treadmill exercise and BMSC transplantation might be one of the effective treatment strategies for recovering sciatic nerve injury-induced neuropathic pain over time.
Gluteus medius muscle strengthening exercise effects on medial longitudinal arch height in individuals with flexible flatfoot: a randomized controlled trial
Authors: Engkananuwat Phoomchai , Kanlayanaphotporn Rotsalai
Published: February 2023

This study aimed to compare the effects of 8 weeks of foot plus hip exercise to foot exercise alone on medial longitudinal arch (MLA) parameters; navicular drop (ND), arch height index (AHI), plantar pressure, static balance, and dynamic balance were measured at baseline, 4 weeks, and 8 weeks. A total of 52 healthy participants with bilateral flatfoot were randomly assigned into foot exercise (n= 26) and foot plus hip exercise (n= 26) group. At 4 weeks, the foot plus hip exercise group showed significantly less ND (P= 0.002), plantar pressure at the medial forefoot (P= 0.002), and mediolateral displacement (P= 0.001) while showing a greater AHI (P= 0.019) than the foot exercise group. At 8 weeks, there was also significantly less plantar pressure at the medial hindfoot (P= 0.017) and less anteroposterior displacement (P= 0.002) in the foot plus hip exercise group than in the foot exercise group. No significant differences between groups were found in dynamic balance. The addition of gluteus medius muscle strengthening exercise to foot exercise was more effective in supporting the MLA than performing foot exercise alone.
The integration of simulation into a post registration neurological course: a phenomenological research study
Authors: Derbyshire Julie Ann , Hill Barry , Diamond-Fox Sadie
Published: February 2023

Background:

Simulation in healthcare education is becoming increasingly popular. However, there is limited evidence of simulation in post registration education or in neurological practice. This article reports on the introduction of simulation into a neurological course for registered nurses and the value of this from the learner perspective.

Aim:

To explore the experiences of nurses who participated in a neurological simulation activity.

Methods:

A phenomenological research design was used to explore the experiences of 10 registered nurses using semi-structured interviews.

Findings:

A total of four key themes were generated from the analysis: being in the spotlight, reality of simulation, theory to practice interface, and learning and working with others.

Conclusion:

The lived experience of the participants of this study has shown that neuro-simulation is valued as a teaching strategy to consolidate learning, with low-fidelity simulation receiving the most positive feedback owing to its authentic nature. A review of the high-fidelity session, where the simulation should become more realistic and use smaller, interprofessional groups, needs to be considered.
SUCCESS OF DAIR VERSUS REVISION IN EARLY AND LATE PJIS IN PRIMARY TKA: A PROSPECTIVE STUDY OF 251 CASES
Authors: Zhu M. , Rahardja R. , Davis J.S. , Manning L. , Metcalf S. , Young S.W.
Published: February 2023

The optimum indications for debridement, antibiotics and implant retention (DAIR) are unclear. Previous studies have demonstrated higher success rate of DAIR within one year of the primary arthroplasty. This study aimed to compare the success rate of DAIR vs revision in “early” and “late” infections to provide guidance for clinical decision making.

The Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort prospectively recorded PJIs between July 2014 and December 2017 in 27 hospitals. This study included PIANO patients with first time PJIs occurring after primary TKA. Treatment success was defined as the patient being alive, free from further revision and without clinical or microbiological evidence of reinfection at two years follow-up.

“Early” and “late” infections were analyzed separately. Univariate analysis compared demographic and disease specific factors between the DAIR and Revision groups. Multivariate binary logistic regression identified whether treatment strategy and other risk factors were associated with treatment success in “early” and “late” infections.

In 117 “early” (<1 year) infections, treatment success rate was 56% in the DAIR group and 54% in the revision group (p=0.878). No independent risk factors were associated with treatment outcome on multivariate analysis.

In 134 “late” (>1 year) infections, treatment success rate was 34.4% in the DAIR group and 60.5% in the revision group (OR 3.07 p=0.006). On multivariate analysis, revision was associated with 2.47x higher odds of success (p=0.041) when compared to DAIR, patients with at least one significant co-morbidity (OR 2.27, p=0.045) or with Staphylococcus aureus PJIs (OR 2.5, p=0.042) had higher odds of failure.

In “late” PJIs occurring >1 year following primary TKA, treatment strategy with revision rather than DAIR was associated with greater success. Patients with significant comorbidities and Staphylococcus aureus PJIs were at higher risk of failure regardless of treatment strategy.
GOING LOW: LOW MODULUS GRAFT-FREE 3D-PRINTED TITANIUM INTERBODY CAGES SHOW COMPARABLE BONE FORMATION TO PEEK WITH GRAFT
Authors: Woodfield T. , Shum J. , Linkhorn W. , Gadomski B. , Puttlitz C. , McGilvray K. , Seim H. , Nelson B. , Easley J. , Hooper G.J.
Published: February 2023

Polyetheretherketone (PEEK) interbody fusion cages combined with autologous bone graft is the current clinical gold standard treatment for spinal fusion, however, bone graft harvest increases surgical time, risk of infection and chronic pain. We describe novel low-stiffness 3D Printed titanium interbody cages without autologous bone graft and assessed their biological performance in a pre-clinical in vivo interbody fusion model in comparison to the gold standard, PEEK with graft.

Titanium interbody spacers were 3D Printed with a microporous (Ti1: <1000μm) and macroporous (Ti2: >1000μm) design. Both Ti1 and Ti2 had an identical elastic modulus (stiffness), and were similar to the elastic modulus of PEEK. Interbody fusion was performed on L2-L3 and L4-L5 vertebral levels in 24 skeletally mature sheep using Ti1 or Ti2 spacers, or a PEEK spacer filled with iliac crest autograft, and assessed at 8 and 16 weeks. We quantitatively assessed bone fusion, bone area, mineral apposition rate and bone formation rate. Functional spinal units were biomechanically tested to analyse range of motion, neutral zone, and stiffness. Results: Bone formation in macroporous Ti2 was significantly greater than microporous Ti1 treatments (p=.006). Fusion scores for Ti2 and PEEK demonstrated greater rates of bone formation from 8 to 16 weeks, with bridging rates of 100% for Ti2 at 16 weeks compared to just 88% for PEEK and 50% for Ti1. Biomechanical outcomes significantly improved at 16 versus 8 weeks, with no significant differences between Ti and PEEK with graft.

This study demonstrated that macroporous 3D Printed Ti spacers are able to achieve fixation and arthrodesis with complete bone fusion by 16 weeks without the need for bone graft. These significant data indicate that low-modulus 3D Printed titanium interbody cages have similar performance to autograft-filled PEEK, and could be reliably used in spinal fusion avoiding the complications of bone graft harvesting.
Investigation of Depth Camera Potentials for Variable-Rate Sprayers
Authors: Jeon Hongyoung , Zhu Heping
Published: February 2023

Highlights

A commercial depth camera with a custom-designed graphical user interface was evaluated to detect tree canopy.

Measurement variations under different indoor conditions were negligible for practical applications.

Measurement errors ranged from 2.8% to 15.8%, which were acceptable for outdoor applications.

Variation of crabapple canopy detection rate was less than 6% from sunrise to sunset.

Abstract. To reduce crop protection product use and environmental impacts while maintaining application efficacy and convenience for applicators, an automatic variable rate sprayer coupled with a canopy detection sensor is required. A commercial depth camera was tested as a means of detecting the canopy of ornamental and tree crops for the sprayer. A custom-designed graphical user interface was developed to control the depth camera and save RGB and IR images and depth data to a local computer. Indoor evaluations showed that measurements could be influenced by the temperature and illumination; however, the influence was minimal, with a relative error of less than 1% and a maximum difference of 14 mm between the average measurements. The depth camera was able to detect a 31% to 72% area of a 20-mm wide target, and the rates went up 72% to 89% when the target width increased to 40 mm. The depth camera showed acceptable performance in detecting canopy contour changes and had measurement errors of 2.8% to 15.3% while detecting the distances to outdoor crabapple and oak trees. In addition, the depth camera detected tree canopy in various outdoor conditions from sunrise to sunset with reasonable accuracy (less than 10% of relative errors). In terms of measurement stability, the depth camera detected crabapple canopy with less than 6% variations under various illuminations between sunrise and sunset. The results suggested that the performance of the depth camera was adequate for detecting canopy under outdoor conditions for future variable-rate spray applications in ornamental and tree crop production. In addition, the study outlined the performance of the depth camera, which provided a guideline for future applications. Keywords: Machine Vision, Precision Agriculture, Specialty Crop, Stereo Vision, Variable Rate Application.
Optimized Chassis Stability Relative to Dynamic Terrain Profiles in a Self-Propelled Sprayer Multibody Dynamics Model
Authors: Adams Bailey , Darr Matthew , Shah Aditya
Published: February 2023

Highlights

This study presented a new optimization methodology using a prismatic joint with high stiffness and damping.

The virtual suspension model contained the main bodies, an optimization subsystem, and a free-floating cylinder.

Under aggressive terrain, an optimized chassis platform resulted in a 19.5% increase in boom height stability.

Abstract. Multibody dynamics (MBD) models are continuing to be valuable for engineering design and product development, especially regarding subsystem optimization. Most MBD optimization processes begin with a sensitivity analysis of treatment factors and levels to understand how uncertainty in model inputs can be attributed to different sources of uncertainty within model outputs; however, this study developed a new MBD methodology to automatically determine the optimized dynamic chassis suspension responses on each corner of the vehicle from a single simulation for a self-propelled sprayer model as the chosen application use-case. This technique leveraged a prismatic joint (with a high spring stiffness and damping coefficient) connected between the chassis mainframe and the simplified optimization tire to create a distance constraint that held the chassis body at a near-consistent height above the ground. Then the solver optimized the response of the chassis suspension system to maintain a stable chassis platform relative to the terrain beneath it as the vehicle traversed across dynamic terrain conditions. This optimization response was also accomplished by replacing the baseline chassis suspension components with a free-floating cylinder, which permitted the unrestricted, optimized motion needed to keep the chassis body at a near-level position with respect to the roll and pitch profiles of the terrain. For a simulation with an aggressive terrain configuration, the analysis showed that an optimized suspension system resulted in a 46% decrease in operator comfort and a 19.5% increase in overall boom height stability as the boom height control system better maintained a dynamic position closer to the specified target height. Keywords: Boom height, Chassis suspension, Multibody dynamics (MBD), Optimization, Prismatic joint, Simulation, Terrain.
Optimization criteria and design of few-mode Erbium-doped fibers for cladding-pumped amplifiers
Authors: Janvier Pierre-Olivier , Matte-Breton Charles , Monga Kaboko Jean-Jacques , Wang Lixian , Rusch Leslie , LaRochelle Sophie
Published: February 2023

We propose a novel optimization method that combines two design criteria to reduce the differential modal gain (DMG) in few-mode cladding-pumped erbium-doped fiber amplifiers (FM-EDFAs). In addition to the standard criterion that considers the mode intensity and dopant profile overlap, we introduce a second criterion that ensures that all doped regions have the same saturation behavior. With these two criteria, we define a figure-of-merit (FOM) that allows the design of FM-EDFAs with low DMG without high computational cost. We illustrate this method with the design of six-mode erbium-doped fibers (EDFs) for amplification over the C-Band targeting designs that are compatible with standard fabrication processes. The fibers have either a step-index or a staircase refractive index profile (RIP), with two ring-shaped erbium-doped regions in the core. With a staircase RIP, a fiber length of 29 m and 20 W of pump power injected in the cladding, our best design leads to a minimum gain of 22.6 dB while maintaining a DMGmax under 0.18 dB. We further show that the FOM optimization achieves a robust design with low DMG over a wide range of variations in signal power, pump power and fiber length.
High-precision single-pixel 3D calibration method using pseudo-phase matching
Authors: Niu Bin , Zhang Fumin , Huang Haozhen , Hao Zhengfeng , Qu Xinghua
Published: February 2023

Compressive sensing makes it possible to explore two-dimensional spatial information using a single-point detector. However, the reconstruction of the three-dimensional (3D) morphology using a single-point sensor is largely limited by the calibration. Here we demonstrate a pseudo-single-pixel camera calibration (PSPC) method using pseudo phase matching in stereo, which can perform 3D calibration of low-resolution images with the help of a high-resolution digital micromirror device (DMD) in the system. In this paper, we use a high-resolution CMOS to pre-image the DMD surface and successfully calibrate the spatial position of a single-point detector and the projector with the support of binocular stereo matching. Our system achieved sub-millimeter reconstructions of spheres, steps, and plaster portraits at low compression ratios with a high-speed digital light projector (DLP) and a highly sensitive single-point detector.
Weakly coupled graded index heterogeneous nineteen-core few-mode fiber
Authors: Shao Pengshuai , Li Zenghui , Ma Liling , Wang Chun , Li Shuguang , Li Jianshe , Cheng Tonglei
Published: February 2023

We propose a novel heterogeneous nineteen-core four-mode fiber. The heterogeneous core arrangement and trench-assisted structure can significantly suppress inter-core crosstalk (XT). In order to control the number of modes in the core, a low refractive index area is introduced in the core. The number of LP modes and the effective refractive index difference (Δneff) of adjacent modes in the core are controlled by changing the refractive index distribution of the core and the parameters of the low refractive index area in the core. And the mode state of low intra-core crosstalk is successfully realized in the graded index core. After the optimization of fiber parameters, each core can stably transmit four LP modes under the optimal fiber parameters, and the inter-core crosstalk of LP02 mode is less than -60 dB/km. Finally, the effective mode area (Aeff) and dispersion (D) of nineteen-core four-mode fiber in C+L band are described. The results show that the nineteen-core four-mode fiber is suitable for terrestrial and undersea communication systems, data centers, optical sensors and other fields.
System nonlinearity correction based on a multi-output support vector regression machine
Authors: Cui Ji , Cai Si Ao , Feng Guoying
Published: February 2023

In a fringe projection profilometry system, the phase error introduced by the projector's gamma distortion is the main source of errors. To overcome this problem, we present a phase compensation scheme for multi-dimensional harmonic coefficient prediction based on a multi-output support vector regression machine(M-SVR), The scheme first constructs a significant characteristic relationship between phase probability density function (PDF) and phase multi-harmonic coefficients, creates simulation data without a priori knowledge, constructs a data set with a certain sample size, and then trains the M-SVR model. The trained M-SVR model is used to capture the potential features of the experimental distorted phase and output the multi-dimensional harmonic parameters with nonlinear relationships, followed by error compensation of the distorted phase using an immobile point iteration algorithm for the purpose of correcting the system nonlinearity. We demonstrate the validity and stability of the model through simulation and experimental trials. Most importantly, the preprocessed M-SVR model also has the potential to participate in error correction of other measurement experiments with reasonable sample and hyperparameter settings, which greatly saves the time and cost of multiple experiments.
Fiber Bragg gratings inscribed in nanobore fibers
Authors: Xiong Cong , Jiang Wei , Wang Caoyuan , Yu Ruowei , He Jun , Chen Runxiao , Li Xuan , Ying Kang , Cai Haiwen , LIU Ai-Qun , Xiao Limin
Published: February 2023

The nanobore fiber (NBF) is a promising nanoscale optofluidic platform due to its long nanochannel and unique optical properties. However, the applications of NBF are only based on its original fiber geometry without extra functionalities so far, compared with various telecom fiber devices, which may limit its wide applications. Here, the first demonstration of NBF-based fiber Bragg grating (FBG) is introduced by the femtosecond (fs) laser direct writing technique and the ultraviolet (UV) laser phase mask technique, respectively. Moreover, the FBG fabricated via the UV laser was optimized, achieving high reflectivity of 96.89% and preserving of the open nanochannel simultaneously. The NBF-based FBGs were characterized in terms of temperature variation and different liquid-infiltration, showing the high potential in nanofluidic applications.
Single SiGe Quantum Dot Emission Deterministically Enhanced in a High-Q Photonic Crystal Resonator
Authors: Fromherz Thomas , Poempool Thanavorn , Aberl Johannes , Clementi Marco , Spindlberger Lukas , Vukusic Lada , Galli Matteo , Gerace Dario , Fournel Frank , Hartmann Jean-Michel , Schaeffler Friedrich , Brehm Moritz
Published: February 2023

We report the resonantly enhanced radiative emission from a single SiGe quantum dot (QD), which is deterministically embedded into a bichromatic photonic crystal resonator (PhCR) at the position of its largest modal electric field by a scalable method. By optimizing our molecular beam epitaxy (MBE) growth technique, we were able to reduce the amount of Ge within the whole resonator to obtain an absolute minimum of exactly one QD, accurately positioned by lithographic methods relative to the PhCR, and an otherwise flat, a few monolayer thin, Ge wetting layer (WL). With this method, record quality (Q) factors for QD-loaded PhCRs up to Q~1e5 are achieved. A comparison with control PhCRs on samples containing a WL but no QDs is presented, as well as a detailed analysis of the dependence of the resonator-coupled emission on temperature, excitation intensity, and emission decay after pulsed excitation. Our findings undoubtedly confirm a single QD in the center of the resonator as a potentially novel photon source in the telecom spectral range.
High Speed Lasers Based Fiber Optic Systems
Authors: Nagarajan Radhakrishnan , Marsland Robert , Li Benjamin , Verdiell Marc , Wen Paul , Braid Peter , Dzurko Kenneth , Craig Richard
Published: February 2023

The transmitter in a high speed fiber optic system typically consists of a semiconductor laser that is either directly or externally modulated. Although, the small signal modulation bandwidth in semiconductor lasers have exceeded 30 GHz (Fig. 1), external modulation is the preferred method for systems operating at 10 GBit/s and beyond. This has to do with the detrimental effects of laser wavelength chirp under modulation which tends to limit the transmission distance in silica fiber [1]. In long distance fiber transmission using directly modulated lasers at 10 GBit/s, the dispersion limit has also been overcome by techniques [2,3] other than traditional dispersion compensation.
Minimizing the Operating Current of Quantum Well Lasers with Modulation Bandwidth and Optical Power Requirements
Authors: McAdams M. , Zhao B. , Chen T.R. , Feng J. , Yariv A.
Published: February 2023

When semiconductor lasers are used in optical telecommunication and optical interconnect applications, it is desirable to have as low an electrical power consumption as possible, i.e. a low operating current. However, if used in a high data transmission rate system, there may be a minimum requisite modulation bandwidth. In addition, signal-to-noise considerations often demand a minimum optical output power. While lowering the threshold current often improves the bandwidth and output power at a given operating current, it is not true that a laser optimized solely for the lowest threshold current will have the lowest operating current when biased to meet the requirements of a particular system. In this talk we discuss how the laser device parameters are optimized to produce the lowest operating current in applications with given bandwidth and optical power requirements.
Diode Lasers for Industrial Spectroscopy
Authors: Stanton Alan C. , Bomse David S. , Silver Joel A. , Hovde D. Christian , Kane Daniel J. , Oh Daniel B. , Paige Mark E.
Published: February 2023

Visible/near-infrared diode lasers are well-suited for use as spectroscopic light sources in detection of a wide variety of gases by measurement of optical absorption. The high spectral resolution of these devices permits the selective detection of targeted species, while their characteristics of relatively low cost, room temperature operation, and compatibility with fiber optics make them attractive for instrument development. The nominal range of available wavelengths (presently ~0.63 −~2.0 μm for commercially available devices that operate at room temperature) includes absorption bands of numerous gas species that need to be monitored to meet various industrial objectives (e.g. process control, emissions monitoring, toxic gas detection, etc.) While the molecular absorption bands in this spectral region consist mostly of relatively weak overtone or combination bands (some electronic bands are accessible at the shorter wavelengths), detection sensitivities of about 1 ppm-meter or better can be achieved for many gases using frequency or wavelength modulation techniques that permit routine measurement of small optical absorbances.1-2 Sub-ppm measurement sensitivities are easily achieved using simple optical multipass designs if necessary. A partial list of industrially significant gases that may be measured by this approach includes oxygen, water vapor, methane, acetylene, carbon monoxide, carbon dioxide, hydrogen halides, ammonia, hydrogen sulfide, and nitrogen oxides (both NO and NO2). Diode laser- based instruments for measurement of some of these species in process control or environmental monitoring applications are now commercially available.
Tunable Infrared Source by Difference Frequency Mixing Diode lasers and Diode pumped YAG, and Application to Methane Detection
Authors: Waltman S. , Petrov K. , Simon U. , Hollberg L. , Tittel F. , Curl R.
Published: February 2023

Tremendous potential exists for the application of diode laser sources
for high sensitivity detection of atoms and molecules. Some of the
obvious applications include pollution monitoring, medical
diagnostics, industrial process monitoring, and analytic and
atmospheric chemistry applications. Room-temperature, tunable diode
laser sources provide the opportunity for constructing compact,
transportable instrumentation. Unfortunately the wavelengths of most
of the atomic and molecular transitions are not directly accessible
with commercially available, room-temperature diode lasers. In
particular many of the important molecular transitions are in the
mid-infrared spectral region. However, this spectral region is
accessible with difference-frequency-generation (DFG) using visible
and near-IR lasers.
Modeling Considerations for UV Diode Lasers Based on GaN
Authors: Eliseev P. G. , Osinski M.
Published: February 2023

The material parameters of GaN active medium are reviewed and specified for the numerical modeling of both edge- and surface-emitting laser devices. Calculations are presented for the oscillation strength, recombination coefficients, quantum yield and modal gain in GaN/GaAlN heterostructure. Threshold currents below 10 kA/cm2 at room temperature are predicted in optimized diode structures.
TE/TM polarization switching with single longitudinal mode operation in GaAs/AlGaAs MQW DFB Lasers
Authors: Ouchi Toshihiko , Majima Masao , Ikeda Sotomitsu , Ono Takeo , Uchida Mamoru , Handa Yuichi
Published: February 2023

Experimental and theoretical studies on polarization bistability or switching in laser diodes have been investigated[1]-[3]. Using a tensilely strained quantum-well structure, highly efficient polarization switching has been demonstrated in multi-electrode Fabry-Perot lasers[4]. For these devices, however, the switching has been observed with multi longitudinal mode operation, which are not suitable for optical frequency division multiplexing systems.
Demonstration of High Sensitivity Laser Ranging System
Authors: Millar Pamela S. , Christian Kent D. , Field Christopher T.
Published: February 2023

The small size, high efficiency, high reliability and direct modulation capabilities of semiconductor lasers make them extremely attractive for space flight applications. In this paper we report on a high sensitivity semiconductor laser ranging system developed for the Gravity And Magnetic Earth Surveyor (GAMES) for measuring variations in the planet's gravity field [1].
A high-power (~2W) external-cavity cw diode laser tunable from 960 - 980 nm
Authors: Gupta S. , Jones R. J. , Jain R. K. , Walpole J. N.
Published: February 2023

Wavelength-tunable high-power diode lasers with narrow-line widths and diffraction-limited outputs are needed for numerous applications including diode-based nonlinear frequency conversion, coherent radar, coherent free-space communications, and spectroscopic applications. The tapered-amplifier gain-guided design [1] has been shown to be a very effective means for achieving high output powers(>1W cw) in a single-lobed diffraction-limited beam [2,3]. Although single longitudinal mode operation using a master-oscillator-power-amplifier (MOPA) scheme, with a monolithic Bragg reflector for the master-oscillator has been demonstrated [4], these structures have very limited tuning ranges (typically < 3 nm), and involve careful adjustment and regulation of the temperature. Broader tuning ranges (~35 nm) of -1 W power levels were demonstrated subsequently by using an external-cavity grating-tuned configuration at wavelengths near 860 nm [5], followed by demonstration of ~0.5 W power levels at other wavelength ranges. This work reports the first demonstration of broadly-tunable narrow-linewidth high-power operation (~1.8W cw, and up to 3 W quasi-cw) in the 960-980 nm wavelength range, to develop a source that is critical for a number of applications including high-power blue generation via quasi-phase matched doubling and spectroscopic study of saturation characteristics of Er-codoped amplifiers and lasers in a variety of host media.
High-performance folded-cavity surface-emitting InGaAs/GaAs lasers fabricated by ion-beam-etching technique
Authors: Cheng Yong , Yang Gye Mo , Dapkus P. Daniel
Published: February 2023

High performance folded-cavity surface emitting lasers (FCSEL's) utilizing 45° deflection mirrors to couple the light in the horizontal cavity towards the surface are attractive devices for applications to optoelectronic integrated circuits. We report here low threshold current and high efficiency InGaAs/GaAs FCSEL's that employ high quality internal 45° deflectors. A simplified process involving a stop etch to position the surface emitting output mirror close to the waveguide and ion-beam-etching (IBE) to form the 45° deflecting mirror is presented.
Optical Correlation with a Cross-Coupled Spatial Light Modulator
Authors: Juday Richard D.
Published: February 2023

In correlation filtering a spatial light modulator (SLM) is usually modeled as affecting only the phase or only the amplitude of light. Usually it is a one-parameter combination of phase and amplitude that correctly describes the action. We develop an integral equation as a necessary condition that includes the phase and amplitude cross-coupling while optimizing a correlation filter. The phase-only filter is shown as a special case. A technique for solving the integral equation is outlined for a phase-mostly SLM.
Multiple Quantum Well Spatial Light Modulators: Design Considerations
Authors: Hsu T. Y. , Efron U. , Wu W. Y. , Schulman J. N.
Published: February 2023

The optimization of an MQW modulator for both phase and amplitude modulation is reported, along with preliminary structural design for a photoactivated MQW spatial light modulator.
Spatial Light Modulators with Internal Memory
Authors: Walpita L.M.
Published: February 2023

It is increasingly recognized that the ability for optical techniques to provide parallel processing may enable us to greatly enhance the speed capability of computing. To satisfy requirements of parallel optical processing many types of spatial light modulators (SLMs) are now being investigated. In this paper we discuss a SLM with internal memory which is electrically addressable and digitally operated.
Investigation of a 1D GaAs-GaAIAs Multiple Quantum Wells Spatial Light Modulator
Authors: Schnell J. Ph. , Pocholle J.P. , Barbier E. , Raffy J. , Delboulbe A. , Fromont C. , Hirtz J.P. , Huignard J.P.
Published: February 2023

Semiconductors multiple quantum wells (MQW’s) are promising optical materials for their fast response speed, their tailorable optical properties and their technological compatibility with electronic circuits.
Optical Pattern Recognition using an Optically Addressed Spatial Light Modulator.
Authors: Vaerewyck Janine M. , Caulfield H. John
Published: February 2023

The purpose of this paper is to discuss the first results of a continuing study on the use of a Spatial Light Modulator in a pattern recognition system. The specific SLM that is being studied was built by Lockheed Missiles and Space Company Inc. of Palo Alto Ca.1 and is on loan to the University of Alabama in Huntsville. This SLM, an optically addressed device, is being used as a spatial filter in a pattern recognition system. The results of a computer study into the most advantageous use of the SLM will be presented as well as the experimental test plan that has been devised from these results.
Microsecond Switching in Cholesteric Liquid Crystals
Authors: Patel J. S.
Published: February 2023

The helical structure of a cholesteric liquid crystal can be modified or even completely unwound by an applied electric field. This is well understood in terms of the coupling of the electric field to the dielectric anisotropy of the liquid crystal, an effect which is quadratic in the amplitude of the electric field. In this paper we report the measurements of optical switching times for a new effect in cholesteric liquid crystals which arises because of flexoelectric coupling1 and which is linear in the electric field.2
Recent Advances in Applications of Photorefractive Devices for Optical Computing
Authors: Fainman Y.
Published: February 2023

Spatial light modulating devices have received much attention recently, primarily for the numerous functions they can perform in parallel optical computing. Various physical principles have been employed in the construction of these spatial light modulators1-3 (SLMs) e.g., liquid crystal light valves, microchannel SLMs, Si-PLZT SLMs, quantum well devices, ferroelectric liquid crystal devices, membrane SLMs, and photorefractive devices. Conventional optically addressed 2-D spatial light modulators (OSLM) are based on the detection of the spatial light distribution of a writing wave and the generation of an electric field image that is used to drive a device that modulates the reading wave. Most of the conventional OSLMs are fabricated by integrating photosensing devices with electro-optic modulators. Similarly, the devices based on photorefractive effect utilize the photoconductivity and electro-optic effect of the material. In photorefractive devices, the spatial intensity distribution of the interference between input waves generates a spatial charge distribution that is held by the self-induced space charge electric field; via the electro-optic effect, this space charge field modulates the refractive index in the volume of the material; which in turn affects the wave propagation and the spatial light distribution at the output. While the photorefractive devices and the conventional OSLMs based on electro-optic modulators are similar in the physical mechanisms they employ (i.e., photosensitivity and electro-optic effect), they differ in their modulation mechanisms. For example, conventional OSLMs may use amplitude modulation via polarization or phase modulation in thin electro-optic media; photorefractive SLMs, on the other hand, rely on the nonlinear interactions (i.e., mixing) of waves in the volume of thin or thick photorefractive material.
A Spatial Light Modulator Based Optoelectronic Associative Memory
Authors: Chao Tien-Hsin
Published: February 2023

An optical implementation of a spatial light modulator based Hopfield type optical associative memory [1] is introduced. An inner-product scheme [2-5] is utilized in the optical system architecture such that the synapses matrix is realized by storing the memory images in two separated spatial light modulators placed in tandem. This scheme is able to save the memory storage space by up to one order of magnitude and is thus very suitable for optical implementation using spatial light modulators.
Nonlinear optical processes in polymers
Authors: Garito A. F. , Heflin J. R.
Published: February 2023

Nonlinear optical processes in pi-electron systems proceed through highly correlated electron states and resonant excitation within these states provide enhanced third-order optical responses essential for bistability and related phenomena at fast time scales.
Differential quantum well spatial light modulators for high speed optical interconnections and computing
Authors: Lentine A. L. , Chirovsky L. M. F. , D’Asaro L. A. , Kopf R. F. , Kuo J. M.
Published: February 2023

Spatial light modulators (SLMs) are an important component for neural and digital optical computing, photonic switching, and optical interconnections of electronic circuits. For optical neural computing and some photonic switching applications, the time required to write the SLM can be relatively long. However, for digital optical computing, optical interconnections, and other photonic switching applications, SLMs must operate as fast as possible. For these high speed applications, spatial light modulators based on the quantum confined Stark effect (QCSE)[1] are a good choice. The inherent speed of the QCSE is extremely fast (~50-100s of femtoseconds)[2]. In addition, waveguide modulators and normal incidence reflection modulators have been made with a 3 dB bandwidths as high as 20 GHz [3] and 5.5 GHz [4] respectively. To maximize the total throughput (number of channels times the bit rate of each channel) of an array of devices, each device must have a separate electrical access lead. In this paper, we present results on a 2 × 4 array of differential quantum well spatial light modulators, each with an individual access leads. Although the device array is not large, it was made using the same batch fabrication procedures [5] that have yielded symmetric SEED arrays as large as 64 × 32[6], thus the fabrication techniques are extendible to making larger spatial light modulator arrays. The frequency response of the devices had a 3dB bandwidth limit greater than 3 GHz as modulators and greater than 4 GHz as detectors.
Thinned Photoconductor Gallium Arsenide Liquid Crystal Light Valves
Authors: Hebbron M.C. , Venables M.A. , Tunnicliffe D.L.
Published: February 2023

Spatial light modulators (slm's) are electro-optic optical transducers. They are capable of imposing spatially and temporally varying optical intensity information from a signal beam onto a separate probe beam. This isolation of input and output signals allows wavelength, coherence and intensity conversion1. Here we report on the continuing development of a GaAs photoconductor based lclv. Having assessed various candidate photoconductor materials on the basis of intrinsic resistivity, light absorption depth, hole mobility and broadband sensitivity GaAs was identified as being a promising material for use in fast optically addressed lclv's.
Arrays of Focused Beams Generated by the Integration of Fresnel Microlenses with Vertical Cavity Surface-Emitting Laser Arrays
Authors: Rastani K. , Orenstein M. , Kapon E. , Von Lehmen A. C.
Published: February 2023

Availability of two-dimensional source arrays with focused (or collimated) beams is essential for a host of optical information processing, interconnection and communication applications. The advent of vertical cavity surface emitting laser arrays (VC-SELAs)[1,2], for example, creates new possibilities of integration and miniaturization in above applications. In addition, the trend in making such laser arrays matrix addressable could eliminate the need for external amplitude spatial light modulators (SLMs)[3]. In order to make the beams from VC-SELAs suitable for applications such as interconnection, however, their output beams need to be focused (or collimated) (which would otherwise be diverging due to diffraction). Here, we present results of integrating easy to fabricate Fresnel microlens arrays (FMAs) with VC-SELAs by patterning the former on the laser substrate. We used such lenses to collimate beams of individual lasers.(We note that collimation is a case of focusing.)
Ferroelectric Liquid Crystal Spatial Light Modulators And Their Applications
Authors: Johnson Kristina M. , Jared David A. , Slagle Tim , Wagner Kelvin , Mao Chongchang , Robinson Michael G.
Published: February 2023

Spatial light modulators (SLMs) are fundamental component in most optoelectronic computing architectures. They function as two-dimensional input-output data displays, spatial filters, incoherent-coherent light converters, smart detector/emitters, and as neuron planes and connection weights in neural networks. In this paper, we discuss recent advances in the electrical and optical addressing of ferroelectric liquid crystal (FLC) SLMs, and their application to optical neural networks, optical correlators and early vision processing.
Operation Characteristics of a Ferroelectric Liquid Crystal Spatial Light Modulator
Authors: Yamamoto S. , Kato N. , Ebihara T. , Sekura R. , Yamanaka J. , Hoshi H.
Published: February 2023

The operation characteristics of an optically and an ir - laser addressed ferroelectric liquid crystal spatial light modulator using hydrogenated amorphous silicon as the photoconductor is presented.
Variable-Sensitivity Analog Response from an Optically-Addressable Spatial Light Modulator
Authors: Landreth B. , Moddel G.
Published: February 2023

We demonstrate a variable-sensitivity analog response from an optically-addressed spatial light modulator. The device comprises a hydrogenated amorphous silicon photodiode and a surface-stabilized ferroelectric liquid crystal light modulator. The write-light intensity required to obtain 50% readout intensity can be varied continuously from 15 µW/cm2 to 1.5 mW/cm2 by changing the frequency of the applied bias voltage from 100 Hz to 2 kHz.
Electron Beam-Addressed Membrane Light Modulator
Authors: Horsky T.N. , Genetti G.J. , O’Mara D.M. , Schiller C.M. , Warde C.
Published: February 2023

First introduced by Preston1 in 1968, deformable mirror SLMs incorporating a highly reflective membrane as the light modulating element have generated interest within the applied optics community as good candidates for both adaptive optics and projection display applications.2-4 These SLMs exhibit very fast response times, can be read out with high optical efficiency, and in principle can incorporate a very large number of resolution elements. Since a deformable mirror SLM is essentially a two-dimensional phase modulating element with large phase dynamic range, it is well-suited to adaptive optics applications such as wavefront correction and beam steering. With appropriate pixelization of the membrane surface, intensity modulation may be accomplished via the Schlieren readout schemes employed by projection display systems such as the Eidophor5 (G.E.) and the γ-Ruticon6 (Xerox). The construction of a membrane light modulator (MLM) is such that a membrane is deposited over an array of wells with an addressable electrode at the bottom of each well. Thus, the well and its electrode define an individual pixel. The membrane is coated with a thin electrode material held at a static potential. A pixel is activated by establishing a potential difference between the well electrode and the membrane electrode, causing the membrane to deform into the well region in response to electrostatic forces. Hence, the pixel driving voltage induces a local phase modulation on the readout wavefront reflected by the membrane mirror surface.
Optoelectronic Neuron Arrays
Authors: Psaltis Demetri , Grot Annette , Luo Jiafu
Published: February 2023

In this paper, we will describe optoelectronic neuron arrays fabricated monolithically in GaAs.
Research activities on spatial light modulators in Hamamatsu
Authors: Suzuki Yoshiji , Hara Tsutomu , Wu Ming H.
Published: February 2023

Various systems for optical information processing have been proposed.
One-transistor DRAM FLC/VLSI SLM
Authors: Handschy Mark A. , Cotter Lise K. , Cunningham Jim D. , Drabik Timothy J. , Gaalema Stephen D.
Published: February 2023

The low-power switching characteristics of FLCs make them especially suit­able for use in spatial light modulators (SLMs) that will updated a frame at a time.
Achromatic Intensity Modulator
Authors: Stockley J. E. , Sharp G. D. , Doroski D. , Johnson K. M.
Published: February 2023

The limits of polarization rotation as a means of intensity modulation can be significantly improved using a system employing chiral smectic liquid crystals.
The requirements for spatial light modulators for optical interconnection
Authors: Ichikawa Hiroyuki , McArdle Neil , Taghizadeh Mohammad R.
Published: February 2023

The spatial light modulator (SLM) is an instrument for real-time wavefront transformation.
Enhanced Performance of AlGaAs/GaAs Asymmetric Fabry-Perot Reflection Modulators
Authors: Gross M. A. , Kenan R. P. , Tran T. K. , Summers C. J.
Published: February 2023

Optical bandwidth and contrast are key to the performance of all-optical asymmetric Fabry-Perot (ASFP) reflection modulators.
Optically addressed liquid crystal phase only modulating spatial light modulator
Authors: Yoshida N. , Mukohzaka N. , Hori T. , Toyoda H. , Kobayashi Y. , Hara T.
Published: February 2023

In the optical information processing such as remote sensing, optical communication and optical computing, numerous optical systems such as adaptive optics have been studied to retrieve the phase information assosiated with the information transmission.