bluuebunny/crossref_metadata_2025 huggingface dataset:
Reining in Onion Prices by Introducing a Vertically Differentiated Substitute: Models, Analysis, and Insights
Authors: Yayla-Küllü H. Müge , Palsule-Desai Omkar D. , Gavirneni Srinagesh
Published: September 2022

Problem definition: Onion is an indispensable ingredient of the Indian diet, and plays a vital role in Indian economy, society, and politics. The ever-lasting volatility in its prices leads to significant social unrest. In this paper, we are interested in helping decision makers to rigorously evaluate a recent policy proposal to make dehydrated onion widely available to remedy the situation. Methodology/results: Using a stylized analytical model, we look for conditions under which it is optimal to introduce a processed substitute and whether it should be managed by nonprofit or for-profit firms. We find that the solution is identified by threshold-based policies and outcomes are far better under the nonprofit management. We also find that a nonprofit processing firm may purposefully choose a strategy where consumers do not purchase its offering for a certain medium range of raw onion deterioration levels. In addition, we find that a for-profit firm would always choose to be the lower-quality substitute in the market unless the raw onion deterioration is high. We also find that when supply capacity is constrained, sales of the processed substitute might decrease with increased supply availability. Managerial implications: This is the first paper that takes perishability and consumer welfare into account in a two-period vertically differentiated market model and compares various scenarios of competition when there is consumer prejudice for the processed substitute. For India’s policymakers, we find ample evidence to work toward implementing the processed substitute policy. We go deep and discuss tailored insights for certain regions in India. We find that although improved consumer perception is favorable in general, policymakers should be careful about some unintended consequences such as increased prices and lower availability.

Funding: O. D. Palsule-Desai acknowledges financial support provided by Indian Institute of Management Indore.

Supplemental Material: The e-companion is available at https://doi.org/10.1287/msom.2022.1145 .
Clues to Bradycardia in a Psychiatric Patient can be Revealed by Good History-Taking: A Case Report and Literature Review
Authors: Abu-Abaa Mohammad , Al-Mohammed Maryam , Mousa Aliaa
Published: September 2022

Lithium is a medication commonly used as a mood stabilizer and can have numerous long-lasting side effects. In this case report, we aim to remind clinicians of such consequences. A 68-year-old woman with a psychiatric history presented for mild COVID-19 and developed sinus bradycardia. A permanent pacemaker was planned for her but was cancelled following good history-taking which revealed prior lithium use. The patient was found to have hyperparathyroidism and hypothyroidism, treatment of which resolved the bradycardia. This case serves to remind clinicians that history-taking remains of paramount importance as in this scenario of bradycardia in a psychiatric patient. An invasive therapeutic measure was precluded by good history-taking. There are several mechanisms by which hypothyroidism and hyperparathyroidism can induce bradycardia. COVID-19 infection can also induce bradycardia.
Playing with Liquid Crystals: A Short Review
Authors: Chakravorty Santanu , Saha Soumen
Published: September 2022

The liquid crystal structure is a distinct phase of matter seen between crystalline and isotropic regions. There are many types of glossy liquids, depending on the composition. They have a different type of electronic device and display. As a result, development and integration of this type of extraordinary materials is required. Here, we have outlined the preparation route and properties of the different compounds which show this type of properties.
Development and Validation of a Green UPLC Analytical Procedure for Glibenclamide Determination in Pharmaceutical Product Using Response Surface Methodology
Authors: Ibrahim Mohamed Abbas , Alshora Doaa Hasan , Alowayid Malak Ahmed , Alanazi Nouf Ayed , Almutari Rayan Ali
Published: September 2022

Glibenclamide (GB) is one of the drugs that is used in the first line for the management of the diabetes mellitus. The aim of this work is to develop a unique green UPLC analytical procedure to analyze GB in pharmaceutical products by implementing QbD (Quality by Design) approach. 32 full factorial design was applied to study the effect of three levels of formic acid (X1; 0.05-0.5%) and temperatures (X2; 25-55oC), for their effects on retention time (Y1), peak area (Y2), peak height (Y3), and HPLC-EAT; environmental assessment tool (Y4). A green mobile phase, which is composed of Methanol 70% and water 30% containing different concentrations of formic acid, was pumped in Isocratic elution mode at a flow rate of 0.2 ml/min, with a total run time of 3.0 min with UV detection at 225 nm. Subsequently, this method was successfully validated using several validation parameters according to ICH guidelines. The results showed that temperature had a significant indirect effect on retention time (P value = 0.001), while formic acid concentration had a significant indirect impact on Peak Area (P value = 0.0101). The peak height was highly affected with formic acid concentration as well as the temperature with P < 0.005. Furthermore, HPLC-EAT was highly affected by column temperature in an indirect way. The optimized green method was discovered to be acceptable in terms of selectivity, precision, accuracy, robustness, sensitivity, and specificity. Moreover, the method efficaciously separated GB peak in the presence of its degradation products in different harsh conditions, revealing stability-indicating property.
Characterization of Blended Polymer Electrolyte Thin Films Based on PVDF + PEG Doped with Nano SiO2
Authors: Ramana K. Venkata , Shekar M. Chandra , Reddy V. Madhusudhana
Published: September 2022

Solution Casting Technique (SCT) is used to prepare the films of poly vinylidene difluoride (PVDF) + poly ethylene glycol (PEG) + nano silicon dioxide (SiO2.). Modifications in structure, thermal stability and energy band gap values of all prepared thin films have been studied using XRD, SEM, DSC and UV-Vis. The disappearance of a small dip at higher concentrations of DSC plots of nano SiO2 in PVDF+PEG indicates that the decrease in the crystallinity which also supported by XRD results. From the SEM results it is observed that, at 10 wt.% of nano SiO2 of concentration amorphous nature is more which leads increase in thermal stability of the material. FTIR results show strong growth in the CF2 stretching with increasing concentratration of nano SiO2 in PVDF+PEG and also the intensity of the aliphatic C-H scattering vibrational bands are observed in spectra of PVDF+PEG and PVDF+PEG+nano SiO2. The direct band gap values of PVDF+PEG+nano SiO2 polymer electrolyte indicates the influence of nano SiO2 on PVDF+PEG for better conducting properties.
Rheology of Gums Used in the Food and Flour Industry for "Tortillas"
Authors: Stanciu Ioana
Published: September 2022

Food gums are hydrophilic colloids, which due to their functional properties are used in the food industry. For non-Newtonian rubber solutions to these factors must be added the dependence between the shear stress and the shear rate. Experimental data were obtained with a Haake RV20 rotary viscometer with a con-plate system. The range of shear speeds for which the determinations were made was between 24 and 3177s-1, and the shear stresses between 2.2 and 116.9Pa.
Temporal trends in comorbidity in adult elective hip and knee arthroplasty patients in England
Authors: Penfold Chris M. , Judge Andrew , Sayers Adrian , Whitehouse Michael R. , Wilkinson J. M. , Blom Ashley W.
Published: September 2022

Aims

Our main aim was to describe the trend in the comorbidities of patients undergoing elective total hip arthroplasties (THAs) and knee arthroplasties (KAs) between 1 January 2005 and 31 December 2018 in England.

Methods

We combined data from the National Joint Registry (NJR) on primary elective hip and knee arthroplasties performed between 2005 and 2018 with pre-existing conditions recorded at the time of their primary operation from Hospital Episodes Statistics. We described the temporal trend in the number of comorbidities identified using the Charlson Comorbidity Index, and how this varied by age, sex, American Society of Anesthesiologists (ASA) grade, index of multiple deprivation, and type of KA.

Results

We included 696,504 and 833,745 elective primary THAs and KAs respectively, performed for any indication. Between 2005 and 2018, the proportion of elective THA and KA patients with one or more comorbidity at the time of their operation increased substantially (THA: 20% to 38%, KA: 22% to 41%). This was driven by increases in four conditions: chronic obstructive pulmonary disease (COPD) (2018: ~17%), diabetes without complications (2018: THA 10%, KA 14%), myocardial infarction (2018: 4%), and renal disease (2018: ~8%). Notably, renal disease prevalence increased from < 1% in 2005 to ~8% in 2018.

Conclusion

Between 2005 and 2018 there were significant changes in the number of comorbidities recorded in patients having elective primary THAs and KAs. Renal disease is now one of the most prevalent comorbidities in this patient population. Future research should explore whether this comorbidity trend has increased the burden on other medical specialities to optimize these patients before surgery and to provide additional postoperative care. Cite this article: Bone Joint J 2022;104-B(9):1052–1059.
Estimating incidence rates of periprosthetic joint infection after hip and knee arthroplasty for osteoarthritis using linked registry and administrative health data
Authors: Jin Xingzhong , Gallego Luxan Blanca , Hanly Mark , Pratt Nicole L. , Harris Ian , de Steiger Richard , Graves Stephen E. , Jorm Louisa
Published: September 2022

Aims

The aim of this study was to estimate the 90-day periprosthetic joint infection (PJI) rates following total knee arthroplasty (TKA) and total hip arthroplasty (THA) for osteoarthritis (OA).

Methods

This was a data linkage study using the New South Wales (NSW) Admitted Patient Data Collection (APDC) and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), which collect data from all public and private hospitals in NSW, Australia. Patients who underwent a TKA or THA for OA between 1 January 2002 and 31 December 2017 were included. The main outcome measures were 90-day incidence rates of hospital readmission for: revision arthroplasty for PJI as recorded in the AOANJRR; conservative definition of PJI, defined by T84.5, the PJI diagnosis code in the APDC; and extended definition of PJI, defined by the presence of either T84.5, or combinations of diagnosis and procedure code groups derived from recursive binary partitioning in the APDC.

Results

The mean 90-day revision rate for infection was 0.1% (0.1% to 0.2%) for TKA and 0.3% (0.1% to 0.5%) for THA. The mean 90-day PJI rates defined by T84.5 were 1.3% (1.1% to 1.7%) for TKA and 1.1% (0.8% to 1.3%) for THA. The mean 90-day PJI rates using the extended definition were 1.9% (1.5% to 2.2%) and 1.5% (1.3% to 1.7%) following TKA and THA, respectively.

Conclusion

When reporting the revision arthroplasty for infection, the AOANJRR substantially underestimates the rate of PJI at 90 days. Using combinations of infection codes and PJI-related surgical procedure codes in linked hospital administrative databases could be an alternative way to monitor PJI rates. Cite this article: Bone Joint J 2022;104-B(9):1060–1066.
Hip arthrodesis in children
Authors: Banskota Bibek , Yadav Prakash , Rajbhandari Ansul , Aryal Rajendra , Banskota Ashok K.
Published: September 2022

Aims

To examine the long-term outcome of arthrodesis of the hip undertaken in a paediatric population in treating painful arthritis of the hip. In our patient population, most of whom live rurally in hilly terrain and have limited healthcare access and resources, hip arthrodesis has been an important surgical option for the monoarticular painful hip in a child.

Methods

A follow-up investigation was undertaken on a cohort of 28 children previously reported at a mean of 4.8 years. The present study looked at 26 patients who had an arthrodesis of the hip as a child at a mean follow-up of 20 years (15 to 29).

Results

The mean Harris Hip Score (HHS) increased from 39.60 (SD 11.06) preoperatively to 81.02 (SD 8.86; p = 0.041) at final review. At latest follow-up, the HHS was found to be excellent in four patients (15%), good in 11 (42%), and fair in 11 (42%). A total of 16 patients (62%) reported mild low back pain, five (19%) had moderate pain, and five (19%) patients had no back pain. Mild ipsilateral knee pain was reported by 19 (73%), moderate pain by one (4%), and no pain by six (23%) patients. Mild contralateral hip pain was reported by ten patients (38%), and no pain by 16 (62%). The 36-Item Short Form Health Survey scores were very good in four patients (15%), good in 18 (70%), and poor in four (15%), with a mean score of 70.92 (SD 12.65). Of 13 female patients who had given birth, 12 did so with uncomplicated vaginal delivery. All patients had to modify their posture for toileting, putting on lower body clothes, foot care, and putting on shoes.

Conclusion

Our results show that with hip arthrodesis, most patients have relatively good function at long-term follow-up, although some pain is experienced in adjacent joints, and modification in some activities of daily living is common. Cite this article: Bone Joint J 2022;104-B(9):1089–1094.
Testing of an Ultrasound-Limited Imaging Protocol for Pavlik harness Supervision (TULIPPS) in developmental dysplasia of the hip: a randomized controlled trial
Authors: Behman Amy L. , Bradley Catharine S. , Maddock Connor L. , Sharma Smriti , Kelley Simon P.
Published: September 2022

Aims

There is no consensus regarding optimum timing and frequency of ultrasound (US) for monitoring response to Pavlik harness (PH) treatment in developmental dysplasia of the hip (DDH). The purpose of our study was to determine if a limited-frequency hip US assessment had an adverse effect on treatment outcomes compared to traditional comprehensive US monitoring.

Methods

This study was a single-centre noninferiority randomized controlled trial. Infants aged under six months whose hips were reduced and centred in the harness at initiation of treatment (stable dysplastic or subluxable), or initially decentred (subluxated or dislocated) but reduced and centred within four weeks of PH treatment, were randomized to our current standard US monitoring protocol (every clinic visit) or to a limited-frequency US protocol (US only at end of treatment). Groups were compared based on α angle and femoral head coverage at the end of PH treatment, acetabular indices, and International Hip Dysplasia Institute (IHDI) grade on one-year follow-up radiographs.

Results

Overall, 100 patients were included; 42 patients completed the standard protocol (SP) and 40 completed the limited protocol (LP). There was no significant difference in mean right α angle at the end of treatment (SP 70.0° (SD 3.2°) ; LP 68.7° (SD 2.9°); p = 0.033), nor on the left (SP 69.0° (SD 3.5°); LP 68.1° (SD 3.3°); p = 0.128). There was no significant difference in mean right acetabular index at follow-up (SP 23.1° (SD 4.3°); LP 22.0° (SD 4.1°); p = 0.129), nor on the left (SP 23.3° (SD 4.2°); LP 22.8° (SD 3.9°); p = 0.284). All hips had femoral head coverage of > 50% at end of treatment, and all were IHDI grade 1 at follow-up. In addition, the LP group underwent a 60% reduction in US use once stable.

Conclusion

Our study supports reducing the frequency of US assessment during PH treatment of DDH once a hip is reduced and centred. Cite this article: Bone Joint J 2022;104-B(9):1081–1088.
Three decades of research on innovation and inequality: Causal scenarios, explanatory factors and suggestions
Authors: Fragkandreas Thanos
Published: September 2022

Prompted by rising income inequality (in short, inequality) in advanced economies, a rapidly growing number of studies across various fields and disciplines of social science have, since the 1990s, sought to find out how innovation (as the main engine of economic progress) affects the distribution of income in modern-day capitalist societies. Using the systematic literature review method, this paper provides the first critical review of 166 studies on innovation and inequality published in 114 journals in the last three decades (1990–2019). It is shown that, while the great majority of studies under review concur that innovation induces inequality, this finding is subject to the disciplinary origins of research (e.g., development studies, economics, geography, innovation studies, etc.) and the country under investigation. Furthermore, guided by an original causally holistic analytical framework, the analysis demonstrates that the relationship between innovation and inequality is significantly more causally complex than the most popular theoretical perspective (i.e., skill-biased technological change account) has let us believe; in particular, it is subject to five causal scenarios and a range of explanatory factors (i.e., skill premiums, technological unemployment, international trade, declining union membership, spatial aspects, changing employment conditions, policy, horizontal inequalities, sectoral composition and types of innovation). The paper ends by discussing findings, policy implications and knowledge gaps, one of which concerns the following under-researched question: how, and under what conditions do publicly funded innovation policies reduce (or increase) inequality?
Shades of gray: Understanding the ethics of society’s technology and innovation propensities using national culture
Authors: Johnson William H.A.
Published: September 2022

This study examines the effects of national culture on national innovation. This is important because underlying values, which relate to national culture and are the basis of ethical stances, are predicted to affect directly country-level innovation propensities, which then can affect national economic well-being. Combining analyses from two databases, the paper explores the relationships between cultural dimensions, which are manifestations of underlying personal values held across a societal group, and national innovation outcomes. The first database uses Hofstede’s national culture dimensions and the other is based on the global innovation index scores of 71 countries. Of the six cultural dimensions, only masculinity/femininity is not found to be significantly related to innovation outcomes. Power distance and uncertainty avoidance negatively relate to innovation outcomes for three and four years, respectively, of the five years tested. Individualism, long-term orientation and indulgence positively relate to innovation outcomes for all five years tested. A major implication is that these cultural variables are important for innovation progress. Findings also suggest that the ethical use of technology and its underlying innovation practices (based on the value systems underlying these cultural dimensions) could benefit from further exploration on the effects of culture. In particular, if a country wants to increase its innovative efforts, it may be well advised to stress individualistic, future-oriented and egalitarian tendencies.
The changing context of innovation management: A critique of the relevance of the stage-gate approach to current organizations
Authors: Trott Paul , Baxter David , Ellwood Paul , van der Duin Patrick
Published: September 2022

The stage-gate method was initially developed as a description of the new product development practices within high-performing firms. At its heart the concept is simple: and the flow of activity of a stage-gate includes project action, information generation, analysis and decision. Research has shown that the stage-gate method has been extremely successful in many contexts. The question of whether the approach is suitable for all projects in all situations is a principal faultline within the literature. Proponents argue that adaptations and evolutions of the stage approach enable it to be universally applied. This paper provides a critical review of the literature and we identify chronic limitations of stage-gate when evaluated against contemporary challenges, including VUCA (volatility, uncertainty, complexity and ambiguity), environment, digitization and open innovation. We remain critical about whether these contemporary currents are best approached by yet another reconfiguration of stage-gate building blocks. We argue that high uncertainty (caused by these currents) requires the flexibility to change fundamental elements of a project, including the underlying concept and the target market, which means that stage-gate is not well suited to innovation processes addressing these contemporary challenges. We propose a typology to show its suitability.
Experimental study of a tapered fiber temperature sensor with a liquid seal based on multimode interference
Authors: Ling Chen , Li Jue , Wang Yiping , Chen Houyuan , Gu Lingyun , Ding Yanwei
Published: September 2022

Studying high-sensitivity fiber-optic temperature sensors is vital in pursuing high-precision temperature measurement. We propose a liquid-sealed multimode interference fiber temperature sensor with a double-taper structure. The influence of structure and sealed-liquid material on the temperature sensitivity of the sensor is analyzed experimentally. The results show that the tapered structure can effectively improve the temperature sensitivity of the sensor, and the effect becomes more evident with the increased refractive index of the sealed liquid. As the refractive index of the sealed liquid increases, the temperature sensitivity of the sensor can be effectively improved. However, the sealed liquid with a high refractive index will increase the failure temperature of the sensor. Near the failure temperature, the sensor achieves an ultra-high-temperature sensitivity of

−

8.28

n
m

/

K

. The results also prove that further increasing the refractive index of the sealed liquid no longer has a significant gain in temperature sensitivity. It is expected that the relevant research will contribute to the development of high-precision temperature-sensing systems.
Development and validation of a hybrid constraint spectral thermometry for laminar sooting flames
Authors: Du Wei , Wen Daxin , Ma Liuhao , Wang Yu
Published: September 2022

A hybrid constraint spectral thermometry (HCST) method based on combined light extinction and spectral soot emission was developed for temperature measurements in sooting flames. Light extinction measurements were performed in the 635–1064 nm spectral range to constrain the fitting of the soot optical property

E
(
m
)

as a function of the wavelength for separately measured spectral emission data. This hybrid constraint methodology helps to avoid complete reliance on either measurement, which significantly increases the immunity of the temperature determination to measurement noises. After numerically validating the performance of HCST, measurements were performed for a series of representative sooting premixed flames. Additional measurements were conducted with the proven tunable diode laser absorption technique to provide a reference temperature, and satisfactory agreements demonstrate the accuracy and robustness of the proposed HCST method.
Long short-term memory network of machine learning for compensating temperature error of a fiber optic gyroscope independent of the temperature sensor
Authors: Cao Yin , Xu Wenyuan , Lin Bo , Zhu Yuang , Meng Fanchao , Zhao Xiaoting , Ding Jinmin , Lou Shuqin , Wang Xin , He Jingwen , Sheng Xinzhi , Liang Sheng
Published: September 2022

We present an artificial intelligence compensation method for temperature error of a fiber optic gyroscope (FOG). The difference from the existing methods is that the compensation model finally determined by this method only uses the FOG’s data to complete the regression prediction of the temperature error and eliminate the dependency on the temperature sensor. In the experimental stage, the proposed method performs temperature experiments with three varying trends of temperature heating, holding, and cooling and obtains sufficient output data sets of the FOG. Taking the output time series of the FOG as the input sample and based on the long short-term memory network of machine learning, the training, validation, and test of the model are completed. From the two perspectives of network learning ability and the improvement degree of the FOG’s performance, four indicators, including root mean square error, error cumulative distribution function, FOG bias stability, and Allan variance analysis are selected to evaluate the performance of the compensation model comprehensively. Compared with the existing methods using temperature information for prediction and compensation, the results show that the error compensation method without temperature information proposed can effectively improve the accuracy of the FOG and reduce the complexity of the compensation system. The work can also provide technical references for error compensation of other sensors.
Assessment of photoreceptor function with ultrafast retinal densitometry
Authors: Bedggood Phillip , Britten-Jones Alexis Ceecee , Ayton Lauren N. , Metha Andrew
Published: September 2022

The optical density of visual pigment can be measured by imaging the dark-adapted eye while bleaching with visible light. This measurement can be made for individual photoreceptor cells using adaptive optics; however, activation of the phototransduction cascade imparts rapid changes in phase that modulate the signal via optical interference. This limits utility because data must be averaged over many experimental runs. Here we used a “flood” illuminated adaptive optics system at 4000 fps, bright light to achieve rapid bleaching, and broad illumination bandwidth to mitigate interference effects. Data were super-resolved using the natural motion of the eye to overcome the reduced pixel resolution of the ultrafast camera. This approach was applied to classify the trichromatic cone photoreceptor mosaic at a single fixation locus within the foveal region of 3 healthy subjects. Subjects were dark adapted for 6 minutes to replenish cone photopigment. This was followed either directly by imaging at 555 ± 50 nm, or by first pre-adapting the retina to 700 nm light to preferentially deplete “L” cone pigment. A total of 3,252 cones were classified as either “S”, “M”, or “L” type based on clustering of the intensity data observed under these two conditions. Mean classification probability ranged from 99.3 to 99.8%, with individual cell probabilities exceeding 95% in 97.0 to 99.2% of cones. Accuracy of cone classification peaked when using the first 10-30 ms of data, with significant reductions in accuracy noted with the inclusion of data from later times. Our results show that rapid bleaching and data acquisition significantly improve the robustness of cell-resolved densitometry.
Multimode quantum squeezing generation via multiple four-wave mixing processes within a single atomic vapor cell
Authors: Qin Wenqiang , Li Jiawei , Chen Zhili , Liu Yuliang , Wei Jiajia , Bai Yonglin , Cai Yin , Zhang Yanpeng
Published: September 2022

Multimode quantum squeezing plays an essential role in the fields of quantum metrology and quantum information. In this paper, we first construct a three- and four-mode energy-level cascaded four-wave mixing system in a single

85

R
b

vapor, and then analyze the quantum properties of the produced states, including the covariance matrix and the intensity squeezing with 11 possible Hamiltonians. In addition, the dressing field is applied to modulate the nonlinear susceptibility and the multimode quantum states. Our scheme allows active modulation of the quantum states integrated within the generation step, without the need for any post-operation of the optics. The mode number of the states also can be extended using more pump fields and the dressing effect. Our study provides a promising candidate to generate multimode quantum states and multimode quantum squeezing within a quantum device involved in the construction of practical quantum networks.
Calibration experiments based on a CO2 absorption cell for the 1.57-µm spaceborne IPDA LIDAR
Authors: Xia Tengteng , Liu Jiqiao , Zhu Xiaopeng , Chen Cheng , Deng Yuxin , Zang Huaguo , Zhang Xiaoxi , Xie Yuan , Yang Juxin , Chen Weibiao
Published: September 2022

The spaceborne IPDA LIDAR has the potential to measure the global atmosphere CO2 column concentrations with high accuracy. For this kind of LIDAR, system calibration experiments in the laboratory are of high importance. In this study, a specially-customized CO2 absorption cell is employed to simulate the CO2 column absorption of the spaceborne platform. Then calibration experiments are constructed for the receiving system and the entire LIDAR system. The absorption of several different XCO2 concentrations from 400 to 415 ppm in the atmosphere is equivalent to that of the absorption cell charged with different pressures of pure CO2. Under the zero pressure of the absorption cell, the calculated equivalent column average concentration (XCO2) is 12.53 ppm, which acts as system bias. In the calibration experiments, the absolute errors are all less than 1 ppm. And the standard deviations (STDs) are less than 1.1 ppm (148-shot averaging) and 0.8 ppm (296-shot averaging) for receiving system and less than 1.2 ppm and 0.9 ppm for the IPDA LIDAR system. All the results of different average times are close to each other and less than 1 ppm, which proves the high accuracy of the IPDA LIDAR system. In addition, the XCO2 concentrations Allan deviation of 0.25 ppm and 0.35 ppm at 100 s shows that the receiving system and IPDA LIDAR system function with long-term stability. Using a CO2 absorption cell as a standard calibration device in the laboratory validates the measurement accuracy and stability of the spaceborne IPDA LIDAR prototype. Furthermore, the proposed absorption cell may serve as a standard calibration device for related atmosphere trace gases sounding research.
High-fidelity temporally-corrected transmission through dynamic smoke via pixel-to-plane data encoding
Authors: Cao Yonggui , Xiao Yin , Pan Zilan , Zhou Lina , Chen Wen
Published: September 2022

We propose a new approach for high-fidelity free-space optical data transmission through dynamic smoke using a series of 2D arrays of random numbers as information carriers. Data to be transmitted in dynamic smoke environment is first encoded into a series of 2D arrays of random numbers. Then, the generated 2D arrays of random numbers and the fixed reference pattern are alternately embedded into amplitude-only spatial light modulator, and are illuminated to propagate through dynamic smoke in free space. Real-time optical thickness (OT) is calculated to describe temporal change of the properties of optical wave in dynamic smoke environment, and transmission noise and errors caused by dynamic smoke are temporally suppressed or corrected. Optical experiments are conducted to analyze the proposed method using different experimental parameters in various scenarios. Experimental results fully verify feasibility and effectiveness of the proposed method. It is experimentally demonstrated that irregular analog signals can always be retrieved with high fidelity at the receiving end by using the proposed method, when average optical thickness (AOT) is lower than 2.5. The proposed method also shows high robustness against dynamic smoke with different concentrations. The proposed method could open up an avenue for high-fidelity free-space optical data transmission through dynamic smoke.
Broadband dispersion compensating ring-core fiber for orbital angular momentum modes
Authors: Zhao Wenqian , Han Xu , Geng Wenpu , Wang Yingning , Fang Yuxi , Bao Changjing , Wang Zhi , Liu Yan-ge , Ren Yongxiong , Pan Zhongqi , Yue Yang
Published: September 2022

A well designed ring-core fiber can theoretically support numerous orbital angular momentum (OAM) modes with low crosstalk for space-division-multiplexing (SDM) data transmission, which is considered as a promising solution for overcoming the capacity crunch in optical communication network. However, the accumulated chromatic dispersion in OAM-fiber could limit the data speed and transmission distance of communication systems. A potential solution is to insert a dispersion compensation ring-core fiber with opposite-sign of dispersion in the transmission fiber along the fiber link. In this work, we propose a triple ring-core fiber with broadband negative dispersion. A highest negative dispersion of -24.47 ps/(nm·km) at 1550 nm and an average dispersion slope in the C band from -0.182 ps/(nm2·km) to 0.065 ps/(nm2·km) can be achieved to compensate multi-order dispersion. The effects of Ge-doping concentration fluctuation in the high-index ring core and fabrication errors on fiber geometric structures are also investigated. Furthermore, the effective mode area decreases as the widths of high-index rings increase due to the enhanced confinement ability. The designed triple ring-core fiber could offer potential for compensating OAM fiber links with positive dispersions.
Highly stable Q-switched and mode-locked pulse generation from an all-PM figure-9 fiber laser
Authors: Guo Kun , Li Can , Ren Bo , Wang Tao , Wu Jian , Luo Zhichao , Zhou Pu , Jiang Zongfu
Published: September 2022

A highly stable figure-9 Yb-doped fiber laser with all polarization-maintaining (PM) double-cladding fiber is demonstrated. Through leveraging the saturable absorption effect of a nonlinear amplifying loop mirror, both the Q-switched and mode-locked operation are realized by adjusting the pump power. With increasing the pump power from the threshold to the maxima, the repetition rate of the Q-switched pulses is linearly increased from 14.9 kHz to 138.0 kHz with the pulse duration accordingly reduced from 3.9 µs to 970 ns. The corresponding maximum average power and pulse energy are respectively 2.34 W and 17 µJ, which are more than ten times larger than the common material-based Q-switched all-fiber lasers. In addition, in the process of increasing and decreasing the pump power, an optical bistability that manifested as a significant power jumping effect is observed, while its effect on the pulse repetition rate and duration is trivial. Whereas for the single pulse mode-locked operation, a maximum output power of 56.3 mW with a fundamental repetition rate of 12.5 MHz is realized, corresponding to a pulse energy of 4.5 nJ. To the best of our knowledge, it is much higher than the most of previous works concerning figure-9 all-PM-fiber lasers of which the emitted pulse energy is generally less than 1 nJ. After being compressed by a pair of diffraction grating, a minimum pulse width of 378 fs and a maximum peak power of 9.76 kW are respectively obtained. In addition, through characterizing the spectral and temporal properties of the laser source, the excellent stability of both the Q-switched and mode-locked operations is verified.
High-security SCMA-OFDM multi-core fiber transmission system based on a regular hexagon chaotic codebook
Authors: Ding Qiancheng , Liu Bo , Ren Jianxin , Mao Yaya , Wang Junfeng , Ullah Rahat , Zhang Haojing , Wu Xiangyu , Zhang Chenfang , Shi Yan , Shen Shikui , Wang Zelin
Published: September 2022

Sparse code multiple access (SCMA), a new code-domain non-orthogonal technology in the fifth-generation mobile communication (5G), can be modulated by orthogonal frequency division multiplexing (OFDM) to improve the link quality of a single user. In this paper, a high-security SCMA-OFDM multi-core fiber transmission system based on a regular hexagonal chaotic codebook is proposed for next-generation passive optical network (PON). The whole encryption process consists of a regular hexagon chaotic codebook design and frequency domain block scrambling. In designing the regular hexagon chaotic codebook, the optimization of constellation points on orthogonal resources are considered as the starting point. Firstly, the chaos factor generated by the four-dimensional Rossler chaos model is deployed to disturb the mother constellation, and then the corresponding chaotic book is formed by rotating the mother constellation and multiplying the sparse matrix. The designed codebook logically avoids the degradation of transmission performance caused by the rough scrambling of codebook constellation, to find a balance between codebook disturbance and bit error rate (BER). The security and reliability of the transmission system have been verified by performing 42 Gb/s encrypted SCMA-OFDM data transmission experiments in a 2km multi-core fiber. The key space of the encryption scheme can reach 10178, which effectively ensures the security of the transmission system. Furthermore, the performance of the transmission system with a regular hexagon chaotic codebook is improved by 2.5 dB compared with the traditional codebook when the BER is 1 × 10−3. Moreover, the SCMA-OFDM-based transmission architecture and the detection effects of different multi-user detection algorithms in the SCMA-OFDM multi-core fiber transmission system are also studied.
Quantitative scattering models of broad-band narrow-beam light through fog
Authors: Liu Yu , Yang Xiao , Zhang Hongjian , Guo Cuixia , Huang Feng
Published: September 2022

A quantitative understanding about the optical scattering of medium plays an important role in many common but important application fields including optical imaging, optical communication, and optical remote sensing. In this paper, two quantitative models about single scattering and multiple scattering were established based on the different polarization properties of these two scattering processes on the condition of paraxial approximation. The related approximate explicit functions about the light scattering characteristics through fog are solved. Moreover, on the basis of scattering models, the depolarization ratio of broad-band polarized light is also measured. The physical models are demonstrated very consistent with the experimental results and Monte Carlo simulations. These works greatly simplify previous models and have a significant promotion to the study of medium scattering characteristics.
Full-aperture random polarization smoothing for a low-coherence laser facility
Authors: Li Fujian , Ji Lailin , Xia Lan , Liu Dong , Shi Haitao , Feng Wei , Rao Daxing , Zhao Xiaohui , Cui Yong , He Ruijing , Xie Qingnan , Li Xiaoli , Ma Weixin , Sui Zhan , Gao Yanqi
Published: September 2022

Two new random polarization smoothing methods using full-aperture elements are proposed on low-coherence lasers, one using birefringent wedge and one using flat birefringent plate. By designing the crystal axis direction and wedge angle of the birefringent plates, the methods can selectively introduce time delay and spatial displacement, so as to obtain fast random evolution of transient polarization by utilizing low spatiotemporal coherence of the laser focal field. Both methods avoid the near field discontinuity and can be used under high fluence. The method using birefringent wedge can slightly improve focal spot uniformity, and the method using flat birefringent plate can obtain non-polarization with DOP lower than 2%. Theoretical studies show that the resulting focal polarization evolves rapidly on sub-picosecond timescales and rapidly covers the entire Poincaré sphere. The method using birefringent wedge is achieved in experiment. The results show that the degree of polarization of the focal spot is reduced from 1 to 0.27, which proves the effectiveness of the full-aperture random polarization smoothing. The full-aperture random polarization smoothing can generate a focal field very close to unpolarized thermal light, which is expected to suppress the laser plasmas instability.
Experimental investigation of the uncertainty principle for radial degrees of freedom
Authors: Zhang Zhihe , Zhang Dongkai , Qiu Xiaodong , Chen Yuanyuan , Franke-Arnold Sonja , Chen Lixiang
Published: September 2022

While the uncertainty principle for linear position and linear momentum, and more recently for angular position and angular momentum, is well established, its radial equivalent has so far eluded researchers. Here we exploit the logarithmic radial position,

ln
 
r

, and hyperbolic momentum,

P
H

, to formulate a rigorous uncertainty principle for the radial degree of freedom of transverse light modes. We show that the product of their uncertainties is bounded by Planck’s constant,

Δ
ln
 
r
·
Δ

P

H

≥
ℏ
/
2

, and identify a set of radial intelligent states that satisfy the equality. We illustrate the radial uncertainty principle for a variety of intelligent states, by preparing transverse light modes with suitable radial profiles. We use eigenmode projection to measure the corresponding hyperbolic momenta, confirming the minimum uncertainty bound. Optical systems are most naturally described in terms of cylindrical coordinates, and our radial uncertainty relation provides the missing piece in characterizing optical quantum measurements, providing a new platform for the fundamental tests and applications of quantum optics.
Noncoaxial RDE of circular asymmetry optical vortex for rotating axis detection
Authors: Qiu Song , Zhu Xiangyang , Tang Ruoyu , Liu Tong , Li Ruijian , Ren Yuan
Published: September 2022

We reveal the mechanism of the noncoaxial rotational Doppler effect (RDE) of an optical vortex and report its application in discriminating the orientation of the rotating axis of the rotating body. In most cases of the RDE-based measurement, the beam axis must be aligned with the rotating axis of the rotational body to observe a good signal. Once the beam axis is not coaxial with the rotating axis, the RDE frequency shift would change related to the misalignment distance, which can be called the noncoaxial RDE. Here, we take the advantage of the misaligned RDE augment with precise light-field modulation and successfully realize the discrimination of the orientation of the rotating axis relative to the illuminating beam. We clarify the principle of noncoaxial RDE and explain why the incomplete optical vortex (OV) is sensitive to the position of the rotating axis. We switch the OV field into four quadrants synchronized with sampling by the data acquisition system, and conduct Fourier transformation of the signals. Combined with the fitting algorithm, the orientation of the rotating axis can be recognized directly. This method may find applications for the noncontact detection of rotating bodies in both industrial and astronomical scenarios.
Low-threshold and narrow-emission random lasing in a self-assembly TiN nanoparticle-doped carbon quantum dot/DCM nanowire composite
Authors: Lyu Jing , Zhang Xinyu , Cai Lei , Tao Li , Ma Weifeng , Li An , Tian Ye , Yin Yunsong , Kong Denan , Yi Wen , Wang Xianshuang , Liu Ruibin
Published: September 2022

The random lasing in quantum dot systems is in anticipation for widespread applications in biomedical therapy and image recognition, especially in random laser devices with high brightness and high monochromaticity. Herein, low-threshold, narrowband emission, and stable random lasing is realized in carbon quantum dot (CQD)/DCM nanowire composite-doped TiN nanoparticles, which are fabricated by the mixture of carbon quantum dots and self-assembly DCM dye molecules. The Förster resonance energy transfer process results in a high luminescence efficiency for the composite of carbon dots and DCM nanowires, allowing significant random lasing actions to emerge in CQD/DCM composite as TiN particles are doped that greatly enhance the emission efficiency through the plasmon resonance and random scattering. Thus, sharp and low-threshold random lasing is finally realized and even strong single-mode lasing occurs under higher pumping energy in the TiN-doped CQD/DCM composite. This work provides a promising way in high monochromaticity random laser applications.
Ultrasensitive and high-speed AlGaN/AlN solar-blind ultraviolet photodetector: a full-channel-self-depleted phototransistor by a virtual photogate
Authors: Lu Jiabing , Lv Zesheng , Qiu Xinjia , Lai Shiquan , Jiang Hao
Published: September 2022

High sensitivity, high solar rejection ratio, and fast response are essential characteristics for most practical applications of solar-blind ultraviolet (UV) detectors. These features, however, usually require a complex device structure, complicated process, and high operating voltage. Herein, a simply structured n-AlGaN/AlN phototransistor with a self-depleted full channel is reported. The self-depletion of the highly conductive n-AlGaN channel is achieved by exploiting the strong polarization-induced electric field therein to act as a virtual photogate. The resulting two-terminal detectors with interdigital Ohmic electrodes exhibit an ultrahigh gain of

1.3
×

10

5

, an ultrafast response speed with rise/decay times of 537.5 ps/3.1 μs, and an ultrahigh Johnson and shot noise (flicker noise) limited specific detectivity of

1.5
×

10

18

(

4.7
×

10

16

) Jones at 20-V bias. Also, a very low dark current of the order of

∼
pA

and a photo-to-dark current ratio of above

10

8

are obtained, due to the complete depletion of the

n
-

Al

0.5

Ga

0.5

N

channel layer and the high optical gain. The proposed planar phototransistor combines fabrication simplicity and performance advantages, and thus is promising in a variety of UV detection applications.
Dual-excitation decoding multiparameter-based ratiometric luminescence thermometry: a new strategy toward reliable and accurate thermal sensing
Authors: Xu Wei , Zong Shuning , Shang Fengkai , Zheng Longjiang , Zhang Zhiguo
Published: September 2022

Luminescence thermometry can perform noninvasive thermal sensing with high spatial resolution and fast response, emerging as an exciting field of research due to its promising applications in biomedicine. Nevertheless, because of the interaction between light and complex tissues, the reliability and the accuracy of this technique suffer serious interference, which significantly restricts its practical utilization. Here, a strategy to implement effective luminescence nanothermometry is preliminarily proposed by employing the different thermal responses between

Yb

3
+

→

Nd

3
+

and

Nd

3
+

→

Yb

3
+

energy transfer processes. Different from the traditional ratiometric sensing method, where two luminescence intensities are used as the thermal response parameters, we use two intensity ratios between

Yb

3
+

and

Nd

3
+

near-IR emissions that are obtained under dual excitation as the detecting and reference signals to perform temperature measurement. This multiparameter-based, self-reference thermometry technique, as we define it, exhibits excellent immunity to the influences arising from the fluctuation and loss of pumping sources as well as the luminescence attenuation in media. High thermal sensitivity (

∼
2.2
%
 

K

−
1

) and good resolution (

∼
0.35
°
C

) are successfully achieved here, accompanied by a measurement error of

∼
1.1
°
C

in a biological environment test, while large errors are observed based on the traditional ratiometric approach (

∼
8.9
°
C
,
∼
23.2
°
C

). We believe the viewpoint in this work could boost luminescence thermometry and provide an ingenious route toward high-performance thermal sensing for biological systems.