bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost effectiveness of Electronic Gate Keeping (EGK) system on laboratory tests demand at a rural academic hospital in Eastern Cape, South Africa: a cross sectional study
Authors: Mayekiso Zoliswa , Oladimeji Kelechi Elizabeth , Pulido-Estrada Guillermo-Alfredo , Hongoro Charles , Apalata Teke
Published: November 2022

Background: Monitoring laboratory expenditure is crucial to ensure that laboratory services remain sustainable and affordable. In South Africa, the National Department of Health (NDoH) and its partner, the National Health Laboratory Services (NHLS) collaborated to introduce Electronic Gate Keeping (EGK) systems across the country. This study estimated the cost-effectiveness of EGK on laboratory tests requested at a rural academic hospital in the Eastern Cape province of South Africa.

Methods: The methodological approach involved the use of a cross-sectional study design. For 24 months (June 2015 to May 2017), data on the number and types of laboratory tests initially requested along with those rejected because there were unnecessary was obtained. Data management and cost effectiveness analysis to estimate cost savings due to EGK on laboratory test demands were carried out using MS Excel and Stata software. There were 28 types of tests requested, of which 22 were chemical tests, two were haematological tests, and four were serological tests.

Results: Out of 448 028 tests requested, 17,480 (3.9%) were rejected after being identified as unnecessary through the EGK system. This rejection rate of 3.9% generated cost savings of USD 51,967.07. The top three tests that generated the most savings were the c-reactive protein (USD 6,077.68), free thyroxine (USD 5,199.92) and hepatitis A IgM (USD 3,813.61).

Conclusions: The study demonstrates that the introduction of EGK has positive spinoffs; it reduced costs, strengthened the dialogue between clinicians and pathologists allowing a platform for continuous education, teaching and learning.
Management of evidence and conflict of interest in guidelines on early childhood allergy prevention and child nutrition: study protocol of a systematic synthesis of guidelines and explorative network analysis
Authors: Sieferle Katharina , Schaefer Corinna , Bitzer Eva Maria
Published: November 2022

Background: With the rising prevalence of allergic diseases in children, prevention of childhood allergies becomes an important public health issue. Recently, a paradigm shift is taking place in the approach to preventing allergies, and clinical practice guidelines (CPG) and food-based dietary guidelines (FBDG) play an important role in providing practitioners with the latest evidence and reliable guidance. However, concern about the methodological quality of the development of FBDGs and CPGs, including limitations in the systematic reviews, lack of transparency and unmanaged conflicts of interest (COI), reduce the trust in these guidelines.

Methods: We aim to synthesize the available guidance on early childhood allergy prevention (ECAP) through a systematic search for national and international CPGs and FBDGs concerning ECAP and child nutrition (CN) and to assess the quality of the guidelines and management of COI. Additionally, we will analyse the content and the evidence base of the recommendation statements. We aim to quantify the COI in guideline panellists and explore possible associations between COI and recommendations. Through a social network analysis, we expect to elucidate ties between panellists, researchers, institutions, industry and other sponsors. Guidelines are an important tool to inform healthcare practitioners with the newest evidence, but quality and reliability have to be high. This study will help identify potential for further improvement in the development of guidelines and the management of COI. If the social network analysis proves feasible and reveals more information on COI in comparison to disclosed COI from the previous analyses, the methodology can be developed further to identify undisclosed COIs in panellists.

Ethics and dissemination: This research does not require ethical approval because no human subjects are involved. Results will be published in international peer-reviewed open access journals and via presentations at scientific conferences.
Effectiveness of nifedipine, labetalol, and hydralazine as emergency antihypertension in severe preeclampsia
Authors: Suhaimi Donel , Novri Dhini Aiyulie , Hamidy Yulis , Savira Maya
Published: November 2022

Background: Preeclampsia is a highly prevalent disease among pregnant women. In the event of hypertensive emergency, nifedipine, labetalol, and hydralazine are assigned as first-line therapies in preeclampsia. Further studies are needed to compare the effectiveness of these drugs to find the most cost-effective drug with minimal side effects. This study aimed to compare the effectiveness of these drugs in lowering blood pressure during hypertensive emergencies in severe preeclampsia.

Methods: 60 pregnant women with severe preeclampsia were recruited in this multiple centre double-blind randomized clinical trial from May 2021 to April 2022 in Indonesia. The patients were divided equally into three groups and treated with three doses of nifedipine, labetalol, and hydralazine, respectively within one hour with 20 minutes interval. The effectiveness was measured based on systolic and diastolic blood pressures, and mean arterial pressure (MAP). The observation was carried out until five hours post-third dose administration.  

Results: The blood pressure was reduced significantly after the administration of the first to the third dose of each antihypertensive (p<0.05). A single dose administration, four, one, and three patients had 20% MAP reduction in nifedipine, labetalol, and hydralazine group. Three, seven, and one patient had a failure of reaching 20% MAP reduction even after receiving the third dose. The effectiveness of the drugs to achieve 20% reduction of MAP could be ranked as follows: nifedipine>labetalol>hydralazine (57.49%, 42.13%, and 40.87%, respectively) for single dose and hydralazine>nifedipine>labetalol (111.3%, 85.12%, and 90.04%, respectively) for triple dose.

Conclusions: Nifedipine is the most effective drug to reduce the blood pressure when single dose administration is used, but requires more doses to further reduce the blood pressure. Hydralazine is the most effective when the drug administration is maxed up to three doses within 60 minutes with 20 minutes interval.

Thai Clinical Trials Registry (TCTR): TCTR20221014007 (14/10/2022)
Evidence of mitochondria origin of SARS-CoV-2 double-membrane vesicles: a review.
Authors: Montes de Oca-B Pavel
Published: November 2022

Coronavirus Disease-19 (COVID-19) pandemic is caused by SARS-CoV-2 that has infected more than 600 million people and killed more than 6 million people worldwide. This infection affects mainly certain groups of people that have high susceptibility to present severe COVID-19 due to comorbidities. Moreover, the long-COVID-19 comprises a series of symptoms that may remain in some patients for months after infection that further compromises their health. Thus, since this pandemic is profoundly affecting health, economy, and social life of societies, a deeper understanding of viral replication cycle could help to envisage novel therapeutic alternatives that limit or stop COVID-19.

Several findings have unexpectedly discovered that mitochondria play a critical role in SARS-CoV-2 cell infection. Indeed, it has been suggested that this organelle could be the origin of its replication niches, the double membrane vesicles (DMV). In this regard, mitochondria derived vesicles (MDV), involved in mitochondria quality control, discovered almost 15 years ago, comprise a subpopulation characterized by a double membrane. MDV shedding is induced by mitochondrial stress, and it has a fast assembly dynamic, reason that perhaps has precluded their identification in electron microscopy or tomography studies. These and other features of MDV together with recent SARS-CoV-2 protein interactome and other findings link SARS-CoV-2 to mitochondria and support that these vesicles are the precursors of SARS-CoV-2 induced DMV. In this work, the morphological, biochemical, molecular, and cellular evidence that supports this hypothesis is reviewed and integrated into the current model of SARS-CoV-2 cell infection. In this scheme, some relevant questions are raised as pending topics for research that would help in the near future to test this hypothesis. The intention of this work is to provide a novel framework that could open new possibilities to tackle SARS-CoV-2 pandemic through mitochondria and DMV targeted therapies.
Engaging health professions students in community-based service learning through the design of a needs assessment survey
Authors: Zeien Justin , Hanna Jeffery , Puracan Jasper , Rosales Cecilia , Hartmark-Hill Jennifer
Published: November 2022

Background: Interprofessional student participation in community-based service learning projects is critically important for the preparation of future health professionals to care for underserved and vulnerable populations. Oftentimes, there is a disconnect between existing community services and the actual needs of individuals being served, such as those experiencing homelessness. A best practice of launching a new service learning project is to begin with a needs assessment. This study describes the stepwise approach taken to guide students launching a new street medicine program in developing and administering a needs assessment survey and is generalizable to other student-led service learning outreaches. Methods: We conducted a needs assessment from April-June 2018 on 144 unsheltered homeless individuals in metro Phoenix, Arizona. The 16-question survey investigated perceptions of priority needs, sources of medical care, health literacy, and health status. Survey results were analyzed using Wilcoxon Rank Sum Test, chi-squared analysis, and multivariable logistic regression. Results: Most respondents (91.6%) identified food as a top need. The majority (64.1%) utilized emergency departments as their primary source of care, and 40.1% reported suboptimal health. Suboptimal health was more likely to be reported in those who expressed transportation (OR 3.03, 95% CI: 1.30-7.07) as a top priority need. Health illiteracy (OR 3.68, 95% CI: 0.76-17.9) was associated with suboptimal health, as was obtaining care at an Emergency Department (OR 2.05, 95% CI: 0.81-5.25). Conclusions: Pairing healthcare with meals and other primary needs may be an effective strategy to increase service utilization by this population. Future needs assessments should consider implementing open-ended questions to better assess the holistic needs of study populations and match community partner organization services with these needs. Needs assessments provide an opportunity for health professional students to learn about social needs and more effectively connect patients with services from community agencies and healthcare organizations.
Constitutionalization of Russian Law in the Teaching of Academician O.E.Kutafin
Authors: Komarova Valentina , Sadovnikova Galina , Narutto Svetlana , Varlen Mariya
Published: November 2022

The collective monograph was written within the framework of the project "Department of Constitutional and Municipal Law of the Kutafin Moscow State Law University: History and Modernity", dedicated to the 85th anniversary of O. E. Kutafin, the founder of the School of Russian Constitutionalism.
For researchers, students, postgraduates and teachers of law schools and anyone interested in the scientific heritage of Academician O. E. Kutafin.
Application of ablation techniques in the treatment of lung cancer - a review of recent reports
Authors: Klas Jakub Michał , Pytka Michalina , Piwowar Klaudia , Kulszo Katarzyna
Published: November 2022

Background: Lung cancer is the second most common and fatal cancer worldwide. The first-line treatment for early-stage primary lung cancer is surgical resection, but surgery is contraindicated in 60% of cases. Alternatives then include local treatments such as radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation. With the current scientific knowledge of these treatments, the fundamental question of their therapeutic efficacy must be answered.
Aim and methods: To present recent scientific findings on the efficacy of the three main methods of thermoablation for lung cancer. A systematic review of scientific papers on the indicated topics from the last 5 years was performed. Several dozen publications were selected for the purpose of this study.
Results: As shown in the studies, the therapeutic effect of MWA controls tumour progression with few side effects and high safety, especially in patients with tumours <3.5 cm in diameter. Cryotherapy, on the other hand, not only improves quality of life, but can also prolong patients' survival. The relatively low risk of this procedure goes hand in hand with its minimal invasiveness, leading to a low complication rate. RFA, on the other hand, shows no greater treatment efficacy than surgical resection, stereotactic radiotherapy. 
Conclusions: MWA and cryoablation techniques are interesting alternatives to surgical resection for non-small cell lung cancer, improving the quality of life of patients regardless of the stage of their disease. The question of increasing the availability of this type of treatment in the health care system therefore remains crucial.
Myasthenia gravis during treatment with anti-PD-1 - succesfull treatment using pirydostygminum – case report and literature review
Authors: Tywanek Ewa , Jankowska Katarzyna , Zwolak Agnieszka , Zgliczyński Wojciech , Łuczyk Robert Jan
Published: November 2022

Background: Against limited effectiveness of known oncological treatment such as chemio-and radiotherapy or surgery, new ways of treatment, such as for example immunotherapy has developed. Usage of immune checkpoint inhibitors (ICPIs), resulting in overactivation of immune system, may significantly raise efficacy of oncological treatment, but simultaneously predispose to occurrence various autoimmunological health complications. Adverse actions of the therapy may affect multiple organs and systems, with the presented example of immune-related neurological complication, myasthenia gravis. This relatively rare condition may be severe, life-threatening illness.
Case report: We present a case of 66-year-old male patient diagnosted with a large tumor histopathologically assessed as squamous cell carcinoma. Due to ineffectiveness of implemented chemio- and radiotherapy, he was qualified for anti-PD1 immunotherapy with nivolumab. General treatment tolerance was very good with positive antineoplastic effect. Autoimmune hypothyroidism has emerged, therefore levothyroxine therapy has been implemented. After about a year of using immunotherapy, significant weakness and decrease in muscle strength has appeared, subsequently, immunotheraphy-related myasthenia gravis was raised. Improvement in the patient's condition was achieved after initiating pyridostigmine treatment. Cessation of antineoplastic treatment wasn’t necessary, what is unusual.
Conclusions:
Undeniably myastenia gravis may determine serious, life-threatening adverse effect of immunotherapy. Usually requires withdrawal of applied antioncological treatment, and should be treated with immunomodulators, immunosuppressants or intravenous immunoglobulins or plasmaphaeresis, however – as we present- in some cases may be properly cured only with pyridostygmine.
Capturing the neglected extremes of UK poverty: a composite modelling approach to destitution and food bank usage
Authors: Bramley Glen , Fitzpatrick Suzanne
Published: November 2022

‘Destitution’ has re-entered the lexicon of UK social policy in the 2010s, highlighted by the rapid growth of food banks and rough sleeping in a context of controversial welfare reforms and austerity policies, yet theoretical literature on this remains limited. Specialist surveys have been developed to measure and profile these phenomena, but these remain separate from the mainstream statistical approach to poverty, which relies heavily on large-scale household surveys. Evidence from recent work in this area, including qualitative evidence, is very suggestive of risk and driving factors, but it is difficult to weigh the relative importance of different factors or to predict the effects of policy measures. A composite survey approach is developed, linking a specialised survey targeting households at risk of destitution with a major national household panel dataset, to enable predictive models to be fitted to data including significant representation of hard-to-reach and non-household populations. Models predicting destitution and food bank usage are developed and compared, highlighting the roles of key factors. Vignettes are used to show how the risks vary dramatically between households in different situations. The potential role of such models in micro-simulation or prediction of impacts of different scenarios is discussed.
Pilot label comprehension study for an over‐the‐counter combined oral contraceptive pill in the United States
Authors: Grindlay Kate , Key Katherine , Bradford Russell D. , Amato Chiara , Blanchard Kelly , Grossman Daniel
Published: November 2022

Context

A growing body of evidence supports over‐the‐counter access to oral contraceptives in the United States. An important consideration for over‐the‐counter approval is consumers' ability to understand key package label messages related to safety and effectiveness without clinician involvement. We developed a prototype over‐the‐counter Drug Facts Label for a combined oral contraceptive pill and conducted a pilot label comprehension study to evaluate consumer understanding of key messages for use.

Methods

In November–December 2020, we conducted interviews with 163 adults and teens in the United States who were aged 12–49 years and identified as female or another gender but had a uterus and the ability to become pregnant. We developed 11 primary endpoints based on assessment of clinical risks that could occur if consumers fail to heed them, including messages about contraindications and directions for use; 11 secondary endpoints represented additional important information but with lower potential for clinical consequences if not understood. We evaluated endpoint comprehension by computing frequencies, percentages, and 2‐sided Exact (Clopper‐Pearson) 95% confidence intervals for observed proportions.

Results

Ten of the 11 primary endpoints and 10 of the 11 secondary endpoints were each understood by ≥95% of participants. The remaining primary endpoint on use with prior blood clots was understood by 89% of participants. The remaining secondary endpoint on the product being designed for “people who have the ability to become pregnant” was understood by 83% of participants.

Conclusion

Participants understood the key label information required for safe and effective combined oral contraceptive use without clinician involvement.
Designing a Fano-resonance-based temperature sensor by side-coupling double cavities to waveguide in photonic crystals
Authors: Wu Hong , Zhang Hua , Li Feng , Su Wei
Published: November 2022

Optical sensors are widely used for temperature measurement in chemistry, biomedical detection, and food processing industries. In this paper, we present a highly sensitive temperature sensor based on the Fano resonance in two-dimensional photonic crystals. A carefully designed double cavity is used within the photonic crystals to symmetrically side-couple to a line-defect waveguide. Due to the direct and indirect coupling between two cavities, we found an asymmetric Fano-like line shape in the transmission spectrum. The optimized quality factor of the Fano resonance and the modulation depth are improved to a maximum of 10672 and above 90%, respectively. Furthermore, the sensitivity of the temperature sensor can reach as high as 91.9 pm/°C, which is direct evidence for its high sensing capability. Thus, our proposed temperature sensor has comparable quality factor and sensitivity with other reported sensors, indicating its high application potential in the sensing field.
Wave-theory-based analysis of a fiber optic bio-sensor illuminated by radially polarized Bessel–Gauss beam: an approach for early diagnosis of breast cancer with a high-resolution wavelength-interrogation technique
Authors: Saha Bijaya , Goswami Nabamita , Saha Ardhendu
Published: November 2022

With the establishment of
validity using authoritative
experimental results, an analytical investigation of an SPR-based
fiber optic sensor, employing a wave-theory-based technique for
determining breast cancer by shining a radially polarized Bessel–Gauss
(RPBG) beam, is proposed. First, by using a radially polarized
Gaussian (RPG) beam, the observed sensitivity is
9404.61 dB/RIU, where the acquired results are in good
concurrence with the experimental data reported by Yan et al. [Chin. Opt. Lett.
7, 909 (2009)COLHBT1671-7694]. Thus, the
proposed theory has been validated with the reported experimental
data. This theoretical analysis is further extended by utilizing an
RPBG beam, where the observed sensitivity is 21,699.26 dB/RIU
and 5846 nm/RIU, with a resolution of

4.61

×

10

−
7

, which is 2.5 times superior to the
reported results to date. By using an RPBG beam, the proposed method,
to our best knowledge, is the first to achieve much higher sensitivity
in the area of fiber optic breast cancer detection. The higher
sensitivity achieved at lower concentrations of an HER2 biomarker has
led to the idea of early diagnosis of breast cancer by optically
assessing it at its earlier stage using a high-resolution
wavelength-interrogation technique.
Improved spectral reflectance model of oil films on seawater based on two-beam interference theory
Authors: Zhang Zhenduo , Feng Xiaojun , Dong Shuang , Xie Ming , Li Wei , Li Ying
Published: November 2022

The theoretical properties of electromagnetic transmission and radiation of light are combined with the propagation law of light in a uniform medium and the Fresnel formula to provide an improved two-beam interference model for simulating oil spills. This model enables the study of spectral reflectance under different thicknesses and different illumination angles. Through observation and analysis of simulation results, it is found that light waves reflected at the interface of water and oil films and of oil films and air oscillate due to interference. In order to overcome this problem, solar irradiance is simulated and multiplied with the reflection model to obtain the outgoing illuminance values at different wavelengths, which are convoluted with the slit function of the hyperspectral camera. The processed results are compared with incoming illuminance values to obtain new simulation results. In addition, based on portable hyperspectral imagery and imported xenon lamp light sources and other experimental equipment, indoor simulated oil spill experiments were conducted. By comparing and analyzing the results of these simulations, the accuracy of the improved model was further improved, demonstrating the feasibility and utility of the model in studying oil spills at water surfaces.
Non-coplanar misalignment optical waveguide cantilever sensor with a monotonic response in a large operation range
Authors: Zhang Hongru , Dai Xingang , Hu Yanjun , Wu Dalin , Jing Gaoshan , Li Yuan , Fan Guofang
Published: November 2022

This paper reports a non-coplanar misalignment optical waveguide cantilever sensor realizing a monotonic response with a large operation range. A

1

×

2

Y-branch optical power splitter cantilever structure was designed, and one of the branches was reduced in thickness at the end, as a non-coplanar structure with respect to another. The misalignment coupling of the two branches due to the thickness of one branch leads to a monotonic response of an optical waveguide cantilever sensor. The simulation results showed a monotonic response with a sensitivity of

6

×

10

−
4

n
m

−
1

in a large operation range of

−

1

to 1 µm.
Prediction of surface roughness in different machining methods using a texture mask feature extraction method
Authors: Pan Hsu-Chia , Pan Jui-Wen , Chang Kao-Der
Published: November 2022

In this study, a texture mask (TM) machine learning method for predicting metal surface roughness produced by different machining methods is proposed. The problems caused by angle deviation in the image acquisition process can be effectively improved, and the training time of the model can be reduced. The surface roughness, with a roughness average (Ra) below 1 um, produced by two similar processing methods, flat lapping and grinding, is examined for prediction and verification. The performances of TM and other feature extraction methods, under different irradiation system conditions and different angle deviations, are also evaluated and compared. The results show that the proposed TM method is more accurate than other methods when the problem of angle deviation occurs. We also compare TM with the convolutional neural network (CNN) method. The accuracy of both methods exceeds 91%, but the training time for TM is significantly less than that of the CNN method. The results show the texture mask method to be an accurate and efficient texture extraction method suitable for use in an automatic system.
Free-Space Luminescent Solar Concentrators for Road- Integrated Photovoltaic Installations
Authors: Bundo Silvi , Pal Shweta , Saive Rebecca
Published: November 2022

This paper evaluates the performance of free-space luminescent solar concentrators for road-integrated photovoltaic installations in the Netherlands. Analysis of configurations show an enhanced power output yield compared to the traditional PV system infrastructure.
Parameter Optimization of Foundry-Enabled Modified Bragg Grating Filters
Authors: Saha Gareeyasee , Ralph Stephen E.
Published: November 2022

The rapid commercialization of silicon photonics necessitates scalable narrow-band filtering elements with high extinction and free spectral range. We design such filters with Particle Swarm Optimization that meet lithography constraints of commercial silicon photonic foundries.
Palm-sized wavelength-multiplexed hologram recorder
Authors: Tahara Tatsuki
Published: November 2022

A palm-sized wavelength-multiplexed hologram recorder for a reflective 3-D object is presented. A color 3-D image is obtained using spatially incoherent color illumination light, wavelength-multiplexed incoherent holograms, and computational coherent superposition scheme.
High-Performance Near-Infrared Spectral Sensors
Authors: van Elst Don M.J. , van Klinken Anne , Ou Fang , Li Chenhui , Petruzzella Maurangelo , Hakkel Kaylee D. , Pagliano Francesco , Sevo Petar , van Veldhoven Rene P.J. , Fiore Andrea
Published: November 2022

We demonstrate a compact and robust near-infrared (900-1700nm) spectral sensor consisting of 16 resonant-cavity-enhanced photodetectors. We achieve a tunable spectral response with narrow linewidth and high responsivity and demonstrate the sensing performance on various applications.
Diffraction of Gaussian and Laguerre–Gauss beams from a circular aperture using the moment expansion method
Authors: Dupraz K. , Martens A. , Rax J. M. , Zomer F.
Published: November 2022

A method based on the distribution theory is introduced to compute the Fresnel diffraction integral. It is applied to the diffraction of Gaussian and Laguerre–Gauss beams by a circular aperture. Expressions of the diffracting field are recast into a perturbation series describing the near- and far-field regions.
Tikhonov regularization-based extended Kalman filter technique for robust and accurate reconstruction in diffuse optical tomography
Authors: Zhang Jie , Zhang Limin , Liu Zongyang , Zhang Yanqi , Liu Dongyuan , Jia Mengyu , Gao Feng
Published: November 2022

Diffuse optical tomography (DOT) is a non-invasive imaging modality that uses near-infrared light to probe the optical properties of tissue. In conventionally used deterministic methods for DOT inversion, the measurement errors were not taken into account, resulting in unsatisfactory noise robustness and, consequently, affecting the DOT image reconstruction quality. In order to overcome this defect, an extended Kalman filter (EKF)-based DOT reconstruction algorithm was introduced first, which improved the reconstruction results by incorporating a priori information and measurement errors to the model. Further, to mitigate the instability caused by the ill-condition of the observation matrix in the tomographic imaging problem, a new, to the best of our knowledge, estimation algorithm was derived by incorporating Tikhonov regularization to the EKF method. To verify the effectiveness of the EKF algorithm and Tikhonov regularization-based EKF algorithm for DOT imaging, a series of numerical simulations and phantom experiments were conducted, and the experimental results were quantitatively evaluated and compared with two conventionally used deterministic methods involving the algebraic reconstruction technique and Levenberg–Marquardt algorithm. The results show that the two EKF-based algorithms can accurately estimate the location and size of the target, and the imaging accuracy and noise robustness are obviously improved. Furthermore, the Tikhonov regularization-based EKF obtained optimal parameter estimations, especially under the circumstance of low absorption contrast (1.2) and high noise level (10%).
Motion: A High speed, low cost, low energy chip scale optical module for co-packaging on a first-level organic substrate for HPC and Data Centers
Authors: Kuchta D. , Meghelli M. , Pepeljugoski P. , Schares L. , Schultz M. , Maniotis P. , Fortier P. , Tucotte E. , Bureau C. , Pion M. , Cossette Y. , Jutras G. , Sow B. , Parikh B. , Ostrander S. , Li S. , Becker D. , Gholami F. , Bagheri H. , Flens F. , Light G. , Wang B.
Published: November 2022

We report on progress and results towards the development of a high speed, low cost, low energy (<4pJ/bit) chip scale optical module for co-packaging on a first-level organic substrate for HPC and Data Center applications.
Optical properties and energy transfer of fluorotellurite glasses doped with Sm3+ and Sm3+:Yb3+ in visible and near-infrared wavelength under three different excitation sources
Authors: Kumi-Barimah E. , Chen Y. , Tenwick R. , Sharma G. , Jha A.
Published: November 2022

Fluorotellurite based glasses have been investigated for numerous optical applications such as lasers, fibre optic, waveguide, and Raman gain devices. The fluorotellurite materials exhibit unique high linear and nonlinear refractive indices ( please add data), extended UV- and IR transparency (0.35 to 5.0µm). Above all the glass host promotes the retention of large concentrations of RE3+-ions in an environment of depleted OH-ions which is advantageous from the point of view of enhanced spectroscopic properties for light amplification in visible and near-IR.
Combination of scattering-projection interleaving and random down-sampling for compressive confocal Raman imaging
Authors: Yuan Hang , Zhang Pengfei , Gao Feng , Bao Xianyu
Published: November 2022

Parallel excitation with an array of foci is one way to improve the speed of Raman hyperspectral imaging, and random interleaving of its projection has been proved to be a successful strategy for reconstructing the compressed data cube. The so-called SIRI method allows single-acquisition compressive confocal Raman imaging and provides excellent reconstruction fidelity at a high compression ratio. Here, we demonstrate that, when scattering-projection interleaving and randomly down-sampling in the spatial domain are combined, the modified SIRI allows a further reduction in the data acquisition time and an expansion of the imaging region. At a moderate down-sampling rate, the modified SIRI is even superior to its precursor in terms of reconstruction fidelity. A maximum compression ratio of 80 is also reported experimentally with the proposed method.
Broadband chaos generation utilizing a wavelength-tunable monolithically integrated chaotic semiconductor laser subject to optical feedback
Authors: Chai Mengmeng , Qiao Lijun , Wei Xiaojing , Li Shuhui , Zhang Chenyang , Wang Qin , Xu Henry , Zhang Mingjiang
Published: November 2022

We demonstrate a broadband and wavelength-tunable chaotic laser by using a monolithically integrated wavelength-tunable chaotic semiconductor laser subject to optical feedback. The chip consists of a gain section, a distributed Bragg reflection grating section, a semiconductor optical amplifier section, and a phase section. By applying an optical feedback loop to the chaotic semiconductor laser chip, a nonlinear frequency mixing is stimulated in the laser cavity, and the chaos bandwidth is expanded to 33.6 GHz, which is 4.4 times larger than the bandwidth without optical feedback. Furthermore, the effect of feedback optical power on the bandwidth is investigated. The results show that the wide power spectrum of chaotic laser is available in a large wavelength range from 1556.44 nm to 1566.42 nm. This work explores a broadband and wavelength-tunable chaotic semiconductor laser for the wavelength division multiplexing to enlarge the capacity in chaotic secure optical communications.
Weak reflectivity measurements of large-mode-area FBGs by a scale composed of a fiber Fabry–Perot interferometer
Authors: Qin Qiushi , Wang Meng , Rao Binyu , Li Hongye , Wang Zefeng
Published: November 2022

In a previous study, we proposed a measuring method for the reflectivity of weak-reflection large-mode-area fiber Bragg gratings by using scale gratings. We experimentally found that the interference between two scale fiber Bragg gratings (FBGs) is beneficial for increasing reflectivity scales, which can improve the measurement accuracy. Therefore, in this study, we designed and fabricated FBG-based Fabry–Perot cavities (FBG-FP) in single-mode fibers by two inscription methods, namely ultraviolet (UV) laser exposure and femtosecond-laser direct writing. Then, a large-mode-area double-clad (LMA-DC) FBG of weak reflectivity was measured by these two scales, and the experimental results show that the Bragg resonance reflectivity is less than 4.28% and 1.14% ∼ 2.28%, respectively. This method of measuring the weak grating reflectivity based on FBG-FP scales is convenient, efficient, and accurate. It is also worth mentioning that the method of femtosecond-laser direct writing eliminates the period limitation of the phase mask, thereby expanding the measurement wavelength range of FBGs. In the future, with the improvement of fiber grating fabrication technology, it is expected that more accurate results can be obtained.
High current short pulse driver using a high power diode laser for optoacoustic biomedical imaging techniques
Authors: Sanchez Miguel , Gallego Daniel , Lamela Horacio
Published: November 2022

Optoacoustic biomedical imaging combines the high spatial resolution of the ultrasound imaging with the specificity of the optical absorption spectroscopy techniques. It is being used in various scenarios such as anatomical, functional and molecular imaging. Typically light sources for this imaging technique is based on solid state lasers since they can produce high energy short optical pulses. However, they are bulky, expensive and the imaging speed is limited because their low pulse repetition rate. High power diode lasers (HPDLs) are a promising alternative for imaging small volume absorbers as they are compact, affordable and allow high repetition rates. However, HPDLs provide relative low peak optical power compared to solid state lasers. Therefore, imaging systems based on diode lasers require much longer pulse duration resulting in lower in-depth resolution and optoacoustic conversion efficiency. HPDLs need dedicated fast electronics to generate short optical pulses. In this work, we have designed, built and test a pulsed diode laser driver based on RF power MOSFETs, specifically considering the optimization of the current pulse in order to maximize the optical peak power, achieving current pulses of more than 900 A with a duration of 50 ns. We have studied the operation of a low cost HPDL out of the manufacturers datasheet ratings without noticeable degradation at high current (> 250 A) and short pulse duration (< 60 ns). We have obtained an optical peak power of 750 W and a energy per pulse of 31.2 µJ at 40 ns optical pulse duration. The optoacoustic images obtained in this operation regime shown a clear enhancement respect to the ones obtained in standard operation of the HPDL.
Depth of field and resolution-enhanced integral imaging display system
Authors: Ma Xiao-Li , Zhang Han-Le , Yuan Rong-Ying , Wang Tong-Yu , He Min-Yang , Xing Yan , Wang Qiong-Hua
Published: November 2022

Depth of field (DOF) and resolution are mutually restricted in integral imaging (II) display. To overcome the trade-offs, we propose an II display system that simultaneously enhances the DOF and resolution. The system consists of a transmissive mirror device (TMD), a semi-transparent mirror (STM), and two II display units. Each II display unit consists of a 4K display screen and a micro-lens array (MLA). Benefiting from the parallel placement of the TMD and the STM, two central depth planes are reconstructed, which effectively enhances the DOF. Meanwhile, the resolution in the overlapping DOF region is increased to two times due to the interpolation of the light field information from two II display units. The impact of the distance between the two II display units and the TMD on the 3D image quality is analyzed. In geometric optics, a distance between the II two display units and the TMD is optimized to eliminate ghost images. In wave optics, a distance is optimized to eliminate 3D pixel gaps by exploiting the diffraction effect of the TMD. Both the geometric and wave optics are considered simultaneously to obtain a high-quality 3D image without ghost images and 3D pixel gaps. A DOF and resolution-enhanced II display system is developed, and the experimental results verify its feasibility.
Switching between topological edge states in plasmonic systems using phase-change materials
Authors: Huang Yin , Shen Yuecheng , Veronis Georgios
Published: November 2022

We introduce non-Hermitian plasmonic waveguide-cavity structures based on the Aubry-Andre-Harper model to realize switching between right and left topological edge states (TESs) using the phase-change material Ge2Sb2Te5 (GST). We show that switching between the crystalline and amorphous phases of GST leads to a shift of the dispersion relation of the optimized structure so that a right TES for the crystalline phase, and a left TES for the amorphous phase occur at the same frequency. Thus, we realize switching between right and left TESs at that frequency by switching between the crystalline and amorphous phases of GST. Our results could be potentially important for developing compact reconfigurable topological photonic devices.
Intensity self-compensation method against multi-factors for polarization-based Fabry–Perot interrogation system
Authors: Li Zhiyuan , Wang Shuang , Jiang Junfeng , Yang Haokun , Zhang Peng , Dai Xiaoshuang , Li Xueping , Liu Tiegen
Published: November 2022

Phase interrogation methods for fiber-optic Fabry–Perot (F-P) sensors may inevitably fail in the field due to the influences of irrelevant factors on signal intensity. To address this severe problem, this Letter proposes an intensity self-compensation method (ISCM) to eliminate the consecutive signal fluctuations of a polarization-based F-P interrogation system caused by multiple factors. By providing only the initial intensities of the reference signals, this attempt realizes the real-time intensity compensation of the output signals without affecting their quadrature relationship. Consecutive intensity fluctuations caused by variation of light source power, fiber loss, and polarization state are reduced to 2%–3% by the ISCM. Furthermore, the method performs ideally under dynamic modulation of the sensor. In addition, it can be applied against the inconsistent fluctuations between signals and is suitable for F-P sensors with single or multiple cavities. Owing to the high efficiency, real-time ability, and no moving parts advantage, the proposed method provides an excellent candidate for improving the accuracy and stability of F-P interrogation systems.
Tapered tip optical fibers for measuring ultra-small refractive index changes with record high sensitivity
Authors: Lu Chunyu , Nikbakht Hamed , Yusuf Erdolu M. , van Someren Bob , Akca B. Imran
Published: November 2022

Here we demonstrate an inexpensive, simple, and ultra-sensitive refractive index sensor based on a tapered tip optical fiber combined with a straightforward image analysis method. The output profile of this fiber exhibits circular fringe patterns whose intensity distribution dramatically changes even with ultra-small refractive index variations in the surrounding medium. The sensitivity of the fiber sensor is measured using different concentrations of saline solutions with a transmission setup consisting of a single wavelength light source, a cuvette, an objective lens, and a camera. By analyzing the areal changes in the center of the fringe patterns for each saline solution, we obtain an unprecedented sensitivity value of 24,160 dB/RIU (refractive index unit), which is the highest value reported so far among intensity-modulated fiber refractometers. The resolution of the sensor is calculated to be 6.9 ×10−9. Moreover, we measure the sensitivity of the fiber tip in the backreflection mode using salt-water solutions and obtained a sensitivity value of 620 dB/RIU. This sensor is ultra-sensitive, simple, easy to fabricate, and low-cost, which makes it a promising tool for on-site measurements and point-of-care applications.
High-power continuous-wave self-frequency-doubled monolithic laser
Authors: Du Jinheng , Chen Xiufang , Yu Haohai , Zhang Huaijin
Published: November 2022

We report a high-power self-frequency-doubled (SFD) Yb:YCa4O(BO3)3 laser by employing a simple and high-integration monolithic configuration with an oscillator length of 6 mm. By reducing the reabsorption and increasing the quantum efficiency, the continuous-wave output power of 21.6 W was obtained with an optical conversion efficiency of 19.0% at the wavelength of about 510 nm. To our knowledge, the results represent the highest output power of a SFD laser. We believe that the high-power SFD laser with a highly compact structure will have broad and promising application prospects in laser display, medical treatment, spectral analysis, scientific research, and other fields.
Effects of UV treatment on the properties of ultra-thin indium tin oxide films during growth and after deposition by cavity ring-down spectroscopy
Authors: Alnaanah Shadi A. , Qatamin Aymen H. , Dieterlen Melanie K. , Mendes Sergio B.
Published: November 2022

In this work, an ultra-sensitive optical absorption technique based on Cavity Ring-Down Spectroscopy (CRDS) was employed to study the effects of UV treatment on the optical properties of ultra-thin indium tin oxide (ITO) films. The ITO films were submitted to UV treatment either after the deposition process or in-situ during the thin-film growth process. Different flow rates of oxygen in the vacuum chamber during film growth were also investigated. An ITO-coated glass substrate inserted in the CRDS cavity at a Brewster’s angle provided a ring-down time of about 1.6 µs, which enabled measurements of optical absorption loss as small as 3 × 10−6. To compare the effects of the UV film treatment, the CRDS technique was employed to measure the extinction coefficient for samples coated with and without the UV treatment. While the optical absorption data was being collected, the electrical resistivity was also simultaneously monitored. The post-deposition UV treatment was found to improve the optical transparency and the electrical performance of ITO film; the optical extinction coefficient of the ultra-thin ITO film is shown to decrease by about 24%. The in-situ UV treatment during growth is also shown to consistently increase the optical transparency of the ultra-thin ITO films and providing outstanding optical performance especially for high flow rates of oxygen during film growth. The electrical resistivity for oxygen flow rates in the range 0.6 - 1.4 sccm is also improved by the in-situ UV treatment, however it shows a sharp increase for oxygen flow rates beyond 1.4 sccm. The CRDS platform is demonstrated here to provide a highly accurate and sensitive methodology for measurement of minute optical absorption losses in ultra-thin films that typically cannot be precisely measured using other conventional spectrophotometric techniques.
High Fill Factor Stretchable Organic Light-Emitting Diodes with Trench Interconnector Structures
Authors: Lee Donggyun , Kim Taehyun , Kim Subon , Kim Junho , Moon Hanul , Yoo Seunghyup
Published: November 2022

Reduction of fill factor during stretching is a chronic problem in stretchable organic light-emitting diodes (SR-OLEDs). Through the trench interconnector structure, we achieved SR-OLEDs with a fill factor of over 80% even after stretching.
Design and Analysis of a Nanostructures based Perovskite LED for Blue Light Emission
Authors: Patwardhan Shubham , Gupta Nikhil Deep
Published: November 2022

The present work studies the design of a nanostructures based perovskite material LED for blue emission. The design optimization and optical analysis confirms the prediction of efficiency improvement and 65% efficiency at comparatively higher injection current is obtained.
Variability in image quality assessment metrics with different image capturing devices
Authors: Wang Y. , Durmus D.
Published: November 2022

Occupants’ subjective evaluations of the visual environment can be estimated using image quality assessment metrics. Images captured by a webcam, iPhone, and HDR camera resulted in only small differences in image quality metrics.
Determination of the Internal Quantum Efficiency of InGaAsP Multiple Quantum wells using Rate Equation Analysis of Photoluminescence Measurements
Authors: Onwukaeme Chibuzo , Ryu Han-Youl
Published: November 2022

The internal quantum efficiency (η
IQE
) of InGaAsP multiple quantum well is determined as a fit parameter from a rate equation of the external quantum efficiency (η
IQE
) as an explicit function of the laser pump power.
Optimized Design of Organic Phototransistors for Enhancing the Photo-induced Source Contact Modulation
Authors: Choi Dongho , Lee Haechang , Park Sanghoon , Moon Hanul , Yoo Seunghyup
Published: November 2022

Organic phototransistors with optimized channel semiconductors, structures, and lateral source/drain geometry are proposed to improve the photo-induced contact modulation. Devices show high light absorption in the channel of 86.6%, the responsivity of 55A/W.
High-beam-quality, Mid-infrared Pulse Delivery over a 118m Length of Low-loss Hollow-Core Fiber
Authors: Fu Q. , Wu Y. , Davidson I. A. , Wheeler N. V. , Xu L. , Poletti F. , Richardson D. J.
Published: November 2022

We report a record low-loss 2.7-4.7 μm guiding hollow-core fiber and its use to deliver high-beam-quality pulses over 118-m-length at 3.12 to 3.57 µm with a maximum 56mW (0.47kW) average (peak) power at 3.25 µm.
Pushing the transmission of silica hollow core fiber towards 5 µm
Authors: Van Newkirk Amy , Lopez J. Enrique Antonio , Correa Rodrigo Amezcua , Schülzgen Axel
Published: November 2022

An ARHCF was designed for 3-5 µm and fabricated from fused silica. Due to strong core confinement, low transmission loss was measured in the MWIR, with only 0.316 dB/m loss at 4.63 µm.
Polycrystalline silver halide fibers and hollow waveguides for Mid InfraRed lasers
Authors: Novikov A. , Usenov I. , Bocharnikov A. , Sakharova T. , Artyushenko V.
Published: November 2022

Polycrystalline Silver Halide PIR-fibers and hollow waveguides transmit Mid IR-radiation in 3-18µm range, but with different parameters. Their pros & cons are compared to enable an optimal choice in coupling with CO2-, CO- and QC-lasers.