bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal socio-economic disadvantage in Aotearoa New Zealand and the impact on midwifery care
Authors: Dixon Lesley , Neely Eva , Eddy Alison , Raven Briony , Bartle Carol
Published: January 2021

Background: Maternal socio-economic disadvantage affects the short- and long-term health of women and their babies, with pregnancy being a particularly vulnerable time. Aim: The aim of this study was to identify the key factors that relate to poverty for women during pregnancy and childbirth (as identified by midwives), the effects on women during maternity care and the subsequent impact on the midwives providing that care. Method: Survey methodology was used to identify Aotearoa New Zealand midwives’ experiences of working with women living with socio-economic disadvantage. Findings: A total of 436 midwives (16.3%) who were members of the New Zealand College of Midwives responded to the survey, with 55% working in the community as Lead Maternity Care midwives, or caseloading midwives, and the remainder mostly working in maternity facilities. The survey results found that 70% of the cohort of midwives had worked with women living with whānau (family) /friends; 69% with women who had moved house during pregnancy due to the unaffordability of housing; 66% with women who lived in overcrowded homes; and 56.6% with women who lived in emergency housing, in garages (31.6%), in cars (16.5%) or on the streets (11%). The cohort of midwives identified that women’s non-attendance of appointments was due to lack of transport and lack of money for phones, resulting in a limited ability to communicate. In these circumstances these midwives reported going to women’s homes to provide midwifery care to optimise the chances of making contact. The midwives reported needing to spend more time than usual referring and liaising with other services and agencies, to ensure that the woman and her baby/ family had the necessities of life and health. This cohort of midwives identified that women’s insufficient income meant that midwives needed to find ways to support them to access prescriptions and transport for hospital appointments. The midwives also indicated there was a range of social issues, such as family violence, drugs, alcohol, and care and protection concerns, that directly affected their work. Conclusion: Recognising the impact of socio-economic disadvantage on maternal health and wellbeing is important to improving both maternal and child health. This cohort of midwives identified that they are frequently working with women living with disadvantage; they see the reality of women’s lives and the difficulties and issues they may face in relation to accessing physical and social support during childbirth.
Practical guide for Earthquake resilient schools
Authors: Amaral Ferreira Mónica , Zapico Blanco Beatriz
Published: January 2021

This guide is intended to be a resource, and not a manual, for increasing the resilience of an educational community, by showing the community what they can do on their own account and how they can strengthen their ability to handle seismic risk (for example, being informed and familiarised with the characteristics that affect the vulnerability of an area in the event of an earthquake, and prepared to protect the students under their tutelage before the earth shakes).
IMPACT-Scot 2 report on COVID-19 in hip fracture patients
Authors: Hall Andrew J. , Clement Nick D. , MacLullich Alasdair M. J. , White Tim O. , Duckworth Andrew D.
Published: January 2021

Aims

The primary aim was to determine the influence of COVID-19 on 30-day mortality following hip fracture. Secondary aims were to determine predictors of COVID-19 status on presentation and later in the admission; the rate of hospital acquired COVID-19; and the predictive value of negative swabs on admission.

Methods

A nationwide multicentre retrospective cohort study was conducted of all patients presenting with a hip fracture to 17 Scottish centres in March and April 2020. Demographics, presentation blood tests, COVID-19 status, Nottingham Hip Fracture Score, management, length of stay, and 30-day mortality were recorded.

Results

In all, 78/833 (9.4%) patients were diagnosed with COVID-19. The 30-day survival of patients with COVID-19 was significantly lower than for those without (65.4% vs 91%; p < 0.001). Diagnosis of COVID-19 within seven days of admission (likely community acquired) was independently associated with male sex (odds ratio (OR) 2.34, p = 0.040, confidence interval (CI) 1.04 to 5.25) and symptoms of COVID-19 (OR 15.56, CI 6.61 to 36.60, p < 0.001). Diagnosis of COVID-19 made between seven and 30 days of admission to hospital (likely hospital acquired) was independently associated with male sex (OR 1.73, CI 1.05 to 2.87, p = 0.032), Nottingham Hip Fracture Score ≥ 7 (OR 1.91, CI 1.09 to 3.34, p = 0.024), pulmonary disease (OR 1.68, CI 1.00 to 2.81, p = 0.049), American Society of Anesthesiologists (ASA) grade ≥ 3 (OR 2.37, CI 1.13 to 4.97, p = 0.022), and length of stay ≥ nine days (OR 1.98, CI 1.18 to 3.31, p = 0.009). A total of 38 (58.5%) COVID-19 cases were probably hospital acquired infections. The false-negative rate of a negative swab on admission was 0% in asymptomatic patients and 2.9% in symptomatic patients.

Conclusion

COVID-19 was independently associated with a three times increased 30-day mortality rate. Nosocomial transmission may have accounted for approximately half of all cases during the first wave of the pandemic. Identification of risk factors for having COVID-19 on admission or acquiring COVID-19 in hospital may guide pathways for isolating or shielding patients respectively. Length of stay was the only modifiable risk factor, which emphasizes the importance of high-quality and timely care in this patient group. Cite this article: Bone Joint J 2021;103-B(5):888–897.
Pediatric Simple Knee Value: A simple patient-reported outcome measure for the knee
Authors: Marot Vincent , Vilette Hugo , Dalmas Yoann , Justo Arthur , Reina Nicolas , Cavaignac Etienne , Berard Emilie , Accadbled Franck
Published: January 2021

Purpose

The pediatric Simple Knee Value (pedi-SKV) is an outcome score in which paediatric patients are asked ‘How would you rate your knee today as a percentage of normal (0% to 100% scale with 100% being normal)?’. The primary aim of this study was to validate the pedi-SKV by measuring its correlation with validated knee function scores used most often in paediatric orthopaedics.

Methods

This prospective study was conducted at a teaching hospital to evaluate the pedi-SKV's validity. A total of 44 paediatric patients (ten to 15 years old), were enrolled prior to anterior cruciate ligament reconstruction as well as 17 healthy controls. A survey form consisting of the Lysholm, International Knee Documentation Committee Pediatric Form (Pedi-IKDC) and pedi-SKV was given to subjects twice (enrolment and six months postoperatively). The criterion validity of the pedi-SKV was determined by correlating it to existing knee functional scores. Responsiveness to change was evaluated by comparing the pedi-SKV scores before and after surgery (enrolment visit and six-month postoperative visit). Discriminative ability was evaluated by comparing the pedi-SKV distribution in patients versus controls.

Results

There was a strong and significant correlation between the pedi-SKV and the Lysholm and Pedi-IKDC (p < 0.0001). The pedi-SKV had a good responsiveness to change (p < 0.0001 for the pedi-SKV before versus six months postoperatively). Like the other knee-specific functional sores (p < 0.0001), the pedi-SKV was able to distinguish between patients and controls (p < 0.0001).

Conclusion

The pedi-SKV is a valid outcome measure that is strongly correlated with the Lysholm and Pedi-IKDC. This is a novel simple score that can be used by physicians in their daily practice.

Level of evidence

II
Review: Winged bean (Psophocarpus tetragonolobus) cropping systems
Authors: Eagleton Graham
Published: January 2021

Abstract. Eagleton GE. 2020. Review: Winged bean (Psophocarpus tetragonolobus) cropping systems. Biodiversitas 21: 5927-5946. Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a rambling, nitrogen-rich, leguminous crop of the Old-World tropics. This review of winged bean (WB) within cropping systems of Southeast Asia and Melanesia revisited four traditional roles that the crop has played: as a minor courtyard vegetable of villages and suburbs throughout the region; as a popular tuber crop in the irrigated plains of Tada-U township in Central Myanmar; as a companion crop in the mixed garden fields of Wamena in Indonesian New Guinea; and as a niche tuber crop in rotation with sweet potato near Goroka in Papua New Guinea (PNG). Drawing upon such traditions, researchers since the 1970s have identified potential new roles for winged bean. In Malaysia, vegetable pod yields up to 35 t ha-1 over a 25-week growing period have been obtained from solidly trellised, branching cultivars. Ratooning the crop through a further two cycles covers the cost of the trellising. Tubers from un-trellised field crops in Myanmar, and of staked, pruned garden crops in highland PNG have been estimated to produce crude protein yields of at least 300 kg ha-1 and 600 kg ha-1, respectively. Synergies between the gene-pools and cultural traditions would be expected to expand the range, raise the yield and stabilize the quality of tuber crop production. Researchers in Sri Lanka intercropped maize with winged bean. At optimal plant densities, they recorded a corn cob yield of 5 t ha-1 together with a cumulative winged bean fresh pod yield of 27 t ha-1. In Kentucky (380N), the combination of maize with winged bean to produce silage resulted in 11-18% greater biomass with 39-67% greater nitrogen per hectare than maize monocrop control plots. Branching winged bean cultivars have significant potential for benign, high-nitrogen cover and forage crops. Promiscuous nodulation and the development of storage root-systems compensate for slow initial top growth which then accelerates to produce a substantial yield of highly digestible leaf protein and vitamins. Hard-seededness and daylength-sensitive phenology are significant, surmountable, barriers to an expanded role for winged beans.
Participatory Mapping of Environment Sanitation Conditions in Settlement of Floating House in Ternate City
Authors: Marasabessy Firdawaty , Aryuni Vrita Tri
Published: January 2021

The water settlement has unique and distinctive characteristics, but it can become an environmental problem if the sanitary conditions are poor. The poor sanitary occurred in the water settlement, namely in Makassar Timur and Mangga Dua Utara, which were initially iconic settlements, but now, both of these settlements have environmental degradation. In line with the Sustainable Development Goals, strengthening community participation was carried out to realize clean water and proper sanitation. The research aimed to map the environmental sanitary conditions by involving community participation. This mapping describes sanitary water settlement characteristics to become a planning database to handle both areas' sustainable hygienic. The results showed that the sanitary achievement index in the two regions, above 50% of the conditions were carried or sufficient. The findings showed the mapping of settlement on the water in the two areas, revealed environment condition with the same characteristics in which the environmental conditions had experienced environmental degradation due to contamination of water bodies because of solid and liquid waste originating from residential houses deliverables from upland settlements. In the future, the settlement environment in Makassar Timur District will be planned to be completely stockpiled. As a result, this environmental area will lose its identity as a settlement on the water. Meanwhile, land conflicts occurred in Mangga Dua Utara District's settlement, resulting in the lack of government programs in this environment to structure slum environmental conditions
Activated Bentonite Modified-Carbon Paste Electrode for Determination The Level of Copper Ion (Cu2+) in Tomato
Authors: Irdhawati Irdhawati , Inur Ingtyas Mawarni Ekki , Jyostosya Yotirani Arya Wijana Ayu , Silvia Sitio Feby , Gita Widi Saraswati Ni Putu , Sahara Emmy
Published: January 2021

Voltammetry is an electroanalytical method measure current as a function of applied potential. The working electrode in the voltammetry method dramatically affects the result of the electrochemical analysis. Modification of the working electrode can improve measurement performance. In this research, the carbon paste electrode (CPE) was modified with Bentonite (CPEB) to determine copper's level using differential pulse voltammetry technique. CPE and CPEB were used as working electrodes, handmade Ag/AgCl as a reference electrode, and Pt wire as the counter electrode. The measurement parameters were optimized, including the composition of bentonite in carbon paste and scan rates. Furthermore, the measurement conditions were validated, involved linear concentration range, detection limit (LoD), the limit of quantization (LoQ), repeatability, and recovery. The results showed that bentonite's optimum composition was 40% of the total weight of graphite and activated bentonite.  The scan rate optimum for Cu2+ measurement was obtained at 20 mV/s with CPE and became faster to be 25 mV/s with CPEB. The linearity of the standard solution measurement of Cu2+ using CPE was in the range of 5 to 100 μg/L and changed to 5 to 500 μg/L using CPEB. LoD and LoQ values of standard solution Cu2+ measurement with CPEB were slower than CPE. The Horwitz ratio calculation was smaller than two for both CPE and CPEB. The recovery of Cu2+ standard measure in sample solution as the matrix was obtained 93,49 ± 6,39%. According to the Decree of the Ministry of Health Number, the level of Cu2+ in the tomato sample was found 6.019 ± 0.69 mg/kg, which is over than threshold value of Cu2+ (5 mg/kg) 03725/B/SK/VII/89.
Land Arrangement for Citronella (Cymbopogon Nardus) and Arabica Coffee in the Cultivation Area in Gayo Lues District, Aceh Province Indonesia: A Land Suitability Approach
Authors: Karim Abubakar , Sugianto Sugianto , Fazlina Yulia Dewi , Rusdi Muhammad , Manfarizah Manfarizah , Hifnalisa Hifnalisa
Published: January 2021

Gayo Lues District is known as Citronella and Arabica coffee producer in Aceh province, Indonesia. This paper aims to manage Citronella and Arabica coffee's land arrangement in the Gayo Lues District's cultivated area.  This implementation is aimed at maintaining the peculiarities of citronella products and Arabica coffee. Thus, the two commodities must be separated in terms of allocated sites.  The altitude for the area is 200-2,000 meters above sea level, consisting of ten classes, and the type of soils are Entisols, Oxisols, Inceptisols, and Ultisols. The area's slope between 0- to 40% (4 classes) was used to delineate the land units. There are 49 land units observed within the cultivated area of 160,017.17 ha.  The guidelines for land suitability classification by the Ministry of Agriculture for Citronella and Center for Coffee and Cocoa Research, Jember for Arabica coffee were utilized.   The results showed that 58,275.5 hectares of land were suitable for citronella, and 13,765.75 ha has been planted. The actual land suitability of citronella inside the area of 58,275.5 ha is suitable (S2 class) and marginally suitable (S3-class) and not suitable (N-class) with limiting factors are temperature, water availability, erosion hazard, and nutrient retention.  This land suitability can be improved by providing inputs to increase the level of suitability with temperature, water availability, and erosion hazard (slope) limiting factors. Also, 48,765.3 hectares can be developed for Arabica coffee, and 4,653.5 ha has been planted.  The actual land suitability for Arabica coffee is Suitable, Marginal Suitable, and Not Suitable, limiting the soil's physical properties (adequate soil depth), slope, and chemical properties of the soil.  Once repaired, the land's suitability becomes Suitable (S1-class) (without limiting factor), Suitable, and marginal suitable with the slope as a limiting factor. There is an area of 44,509.75 hectares of land at 200-1,400 m above sea level within the cultivation area developed with a Citronella. There is an area of 44,111.8 ha at the height of 800-2,000 m above sea level, potentially for  Arabica coffee.
Broadband THz quantum cascade lasers frequency combs: high temperature operation and harmonic state
Authors: Scalari Giacomo , Forrer Andres , Senica Urban , Bosco Lorenzo , Franckié Martin , Beck Mattias , Faist Jérôme
Published: January 2021

We report about high temperature comb operation of THz quantum cascade lasers. The extremely diagonal nature of the optical transition combined with low loss copper-based double-metal waveguides allow CW operation up to 105 K and CW power in excess of 5 mW measured at 80 K. Terahertz emission spanning up to 600 GHz together with a narrow beatnote indicate comb operation at 80 K and strong RF injection modifies clearly the laser spectrum up to 700 GHz spectral bandwidth. Such devices show as well robust harmonic mode locking behaviour and their comb state can be controlled by means of an external tuning element.
Frequency-quadrupled Nd-doped fiber laser source in the deep-UV at 226 nm
Authors: Le Corre Kilian , Gilles Hervé , Girard Sylvain , Barnini Alexandre , Kervella Louanne , Guitton Pascal , Robin Thierry , Santarelli Giorgio , Laroche Mathieu
Published: January 2021

We present the first demonstration of a laser source at 226nm based on the frequency-quadrupling of an all-PM Nd-doped fiber laser. The DUV laser delivers 175mW of average power, 50ns pulse at 30kHz repetition rate.
Raman Amplification of a Single Higher-Order Mode in a 335-m-Long Fiber with a 70-µm-Diameter Step-Index Core
Authors: Zhu Sheng , Feng Yutong , Nilsson Johan
Published: January 2021

A 335-m fiber with a 70-μm diameter, 0.227-NA pure-silica step-index core reaches 15-dB average-power Raman gain for 1112-nm pulses in a high-purity, high-order Bessel-mode (LP07). The 812-W pump peak power is compatible with continuous-wave pumping.
Laser Cooling of a Ytterbium-Doped Silica Optical Fiber Glass Preform
Authors: Mobini Esmaeil , Rostami Saeid , Peysokhan Mostafa , Albrecht Alexander , Kuhn Stefan , Hein Sigrun , Hupel Christian , Nold Johannes , Haarlammert Nicoletta , Schreiber Thomas , Eberhardt Ramona , Tünnermann Andreas , Sheik-Bahae Mansoor , Mafi Arash
Published: January 2021

We report the successful laser cooling of a Ytterbium-doped silica optical fiber glass preform by 0.7K relative to the room temperature. The observed temporal behavior of cooling agrees well with the theoretical predictions.
Tunable Continuous-Wave 2.3-μm Tm3+:KY3F10 Laser Upconversion Pumped with an Ytterbium Fiber Laser
Authors: Morova Yagiz , Tonelli Mauro , Petrov Valentin , Sennaroglu Alphan
Published: January 2021

We report a 2.3-μm Tm3+:KY3F10 laser, which can be excited via upconversion pumping with a 1064-nm ytterbium fiber laser, leading to tunable operation from 2268 to 2373 nm with absorbed power slope efficiency of 32%.
New Saturable Absorbers for Q-switched Visible Lasers
Authors: Ollenburg L. , Tanaka H. , Kränkel C.
Published: January 2021

Two new Co2+-doped spinel crystals generate sub-25-ns pulses from a passively Q-switched Pr3+: YLF laser, the shortest ever reported. Experiments with V3+: YAG crystal indicate the applicability of V3+-doped crystals for visible Q-switching.
Nd:Phosphate Split-Slab Liquid Cooled kJ Amplifier for High Power Laser at High Repetition Rate
Authors: Dalbiès P.M. , Blanchot N. , Bordenave E. , Cadilhon B. , Cavaro S. , Chonion R. , Lavastre E. , Le Palud F. , Lupi J.F. , Manac’h P. , Modin Y. , Paquignon G. , Sajer J.M. , Neauport J.
Published: January 2021

We present the design, experimental results and complete numerical simulation models of a liquid cooled Nd:Phosphate glass split-disk energetic amplifier, operating at 1053nm with a high repetition rate of 1 shot/minute.
Optical Parametric Amplification at Critical Wavelength Degeneracy – a Way towards 100-PW Femtosecond Lasers
Authors: Dabu Razvan
Published: January 2021

At signal critical wavelength, super-broad parametric gain bandwidths can be obtained in nonlinear crystals pumped at degeneracy. Partially deuterated KDP crystals, pumped by green lasers, can amplify ~1.1-μm central wavelength, sub-10 fs laser pulses, up to kJ-energy level.
SESAM-mode-locked Tm:KY3F10 laser at 2340 nm
Authors: Kowalczyk Maciej , Guillemot Lauren , Loiko Pavel , Braud Alain , Doualan Jean-Louis , Benayad Abdelmjid , Hideur Ammar , Sotor Jarosław , Camy Patrice
Published: January 2021

A Tm: KY3F10 laser operating on the 3H4 →3H5 transition (2340 nm) is mode-locked by a semiconductor saturable absorber mirror. A strong etalon effect originating from the SESAM is observed limiting the pulse duration to ~100 ps.
Spectra of superradiant lasers
Authors: Protsenko I. E. , Uskov A. V. , André E. C. , Mørk J. , Wubs M.
Published: January 2021

The emission spectrum of a superradiant laser is calculated analytically using quantum Langevin equations. New sideband peaks and fine structure in the spectrum are predicted for lasers with strong relaxation oscillations.
A 3×1 Laser MMI Power Combiner Based On Slot-Waveguide Technology
Authors: Samoi Eyal , Benezra Yosef , Malka Dror
Published: January 2021

The design of a 3×1 multimode interference power combiner based on a slot waveguide is proposed for reducing losses. Results show that after light propagation of 9.82 µm the beam combiner efficiency can reach 97.6%.
Beam Quality Enhancement in High Power mid-IR ZGP OPO Sources: a Focus on Thermal Lens Build-up
Authors: Piotrowski M. , Medina M. A. , Spindler G. , Schellhorn M. , Hildenbrand-Dhollande A.
Published: January 2021

We reached an optical output power up to 38 W (M2 < 2) in 3 − 5 µm range from a ZGP OPO pumped by a 68 W 10 kHz Ho:LLF MOPA system. We report methods for improvement of beam quality at such power levels and present time-resolved studies of thermal lens.
Investigation on Gain Aperture as a Compact Tool for Spatial Beam Shaping
Authors: Yahia Vincent , Taira Takunori
Published: January 2021

Calculations and experiments show that gain aperture in amplifier can shape a beam, making M2 close to unity under optimized conditions. This effect is modeled and a criterion for optimal effect is derived.
Energy scaling of pre-chirp managed Yb-fiber amplifiers using composite birefringent plates for pulse division and recombination
Authors: Chen Runzhi , Chang Guoqing
Published: January 2021

We propose and analyze pre-chirp managed divided pulse amplification based on composite birefringent plates for pulse division and combination. Yb-fiber system using this technique can deliver <50-fs pulses with GW-level peak power.
Specific Heat of Y3Al5O12 under Cryogenic and Room Temperature Conditions
Authors: Sato Yoichi , Taira Takunori
Published: January 2021

The specific heat (CP) of Y3Al5O12 from -150 °C to 300 °C was evaluated. We can extend the applicable temperature range of our numerical model of CP for Y3Al5O12 to cryogenic region of 200 K.
Towards High Pulse Energy Q-switched Fiber Laser
Authors: Yap Y. K. , Chong W. Y. , Ahmad H.
Published: January 2021

The performance of a MoS2-based Q-switched erbium-doped fiber laser operating with different output coupling ratio was studied. Maximum pulse energy of ~0.50 μJ (~peak power ~186 mW) was achieved with high output coupling ratio.
High-Brightness Unstable Cavity Nd:YAG/Cr4+:YAG Microchip Laser
Authors: Lim Hwan Hong , Taira Takunori
Published: January 2021

Brightness scale of microchip laser was achieved by introducing unstable cavity allowing steady pulse width and 2. A record effective brightness of 0.5 PW/(sr∙2) and 4 times longer effective Rayleigh length than Gaussian were observed.
Laser Induced Coating Damage of Monolithic Solid State Lasers in High-Temperature, Confined Operation
Authors: Andrews A. Ballard , Speck Andrew J.
Published: January 2021

Monolithic solid-state lasers are advantageous in high shock-vibration environments in order to maintain performance. Laser damage thresholds that exceed the laser fluence do not ensure long term reliability without ultra-low polishing contamination. High-temperature confined operation also significantly increases the risk of contamination enhanced laser induced damage on beam steering optics. We report coating performance tests and mitigation strategies.
High resolution temperature sensor based on frequency beating between twin DFB fiber lasers
Authors: Dusablon Laurent , Fortin Vincent , Boilard Tommy , Bernier Martin , Galarneau Pierre , Babin François , Vallée Réal
Published: January 2021

We present a high resolution temperature sensor using the beat frequency between the longitudinal modes of twin single-mode distributed feedback fiber lasers. Experimental results show a sensitivity of 1900 MHz/°C, leading to a precision of 0.0007 °C.
Adjusting the Output of Optical Fiber Lasers by Employing the Filtering from a Spectrum-Modifiable Optical Fiber Modal Michelson Interferometer
Authors: Salceda-Delgado G. , Rodrigués-Carreón V. C. , Martinez-Rios A. , Torres-Torres M. , Vega-Hernandez J. I. , Garza-Sierra. R. O.
Published: January 2021

Adjustment of an optical fiber laser output is presented. It is based on a spectral-modifiable modal Michelson interferometer used as an intra-cavity filter. The laser output wavelength maximums can be adjusted to induce desired emissions.
Enhanced Water-Window Soft X-Ray Emissions from Laser-Irradiated Polyethylene Nanowire Array Targets
Authors: Shou Yinren , Kong Defeng , Wang Pengjie , Mei Zhusong , Cao Zhengxuan , Pan Zhuo , Xu Shirui , Qi Guijun , Chen Shiyou , Zhao Jiarui , Zhao Yanying , Ma Wenjun , Li Yunhui , Luo Wen , Zhang Guoqiang
Published: January 2021

Water-window soft X-ray emissions from polyethylene nanowire array targets irradiated by a 4 × 1019 W/cm2 femtosecond laser were experimentally characterized indicating more than one order of magnitude enhancement in conversion efficiency compared to that from plane targets.
Parametric Generation of Coherent XUV Light
Authors: Hort Ondřej , Dubrouil Antoine , Khokhlova M.A. , Descamps Dominique , Petit Stéphane , Burgy Fréderic , Mevel Eric , Constant Eric , Strelkov Vasily
Published: January 2021

We report experimental observation of a new regime of XUV emission in conditions close to high harmonic generation in gases. It appears as an additional comb of spectral peaks that are stronger than harmonics.
Controlling the temporal shape of a high-power nanosecond 1064 nm laser pulse to explore EUV generation and different droplet deformation regimes.
Authors: Mazzotta Zeudi , Meijer Randy , Kurilovich Dmitry , Schupp Ruben , Versolato Oscar , Eikema Kjeld S. E. , Witte Stefan
Published: January 2021

We describe a laser system capable of delivering ~450mJ pulses with arbitrarily tunable temporal shapes. We show how this shaping affects target deformation and EUV generation when these pulses illuminate liquid tin droplets.
ELI Beamlines User Oriented High-Harmonic Beamline
Authors: Hort Ondřej , Albrecht Martin , Finke Ondřej , Jurkovič Matej , Lera Roberto , Du Mai D. , Klimešová Eva , Espinoza Shirly , Richter Steffen , Antipenkov Roman , Batysta František , Novák Jakub , Green Jonathan T. , Andreasson Jakob , Krikunova Maria , Nejdl Jaroslav
Published: January 2021

We present latest progress and experimental capabilities of user-oriented XUV beamline based on high harmonic generation (HHG). The focal length of the HHG was recently extended to 5 meters, upscaling the overall XUV photon flux.
Multiple Pulses Damage Test on Mo/Si Multilayer Using Table-top Focused EUV Optical System Built at IPOE
Authors: Pan Liuyang , Zhang Zhe , Li Wenbin , Wang Zhanshan
Published: January 2021

We report that EUV damage thresholds follow an inverse-power-law as a function of the pulse number in a S-on-1 damage test on a Mo/Si multilayer, which can be explained by the incubation effect.
Generation and selected applications of the EUV and SXR radiation, emitted from compact laser-plasma sources
Authors: Wachulak P. , Bartnik A. , Duda M. , Fok T. , Węgrzyński Ł. , Adjei D. , Ayele M. , Vysin L. , Fiedorowicz H.
Published: January 2021

Short wavelength radiation with a wavelength from 10 nm to 120 nm is called Extreme ultraviolet (EUV) radiation. Radiation with an even shorter wavelength, i.e. 0.1-10 nm, is called soft X-ray (SXR). EUV and SXR radiation is very strongly absorbed in matter, which allows obtaining high natural optical contrast in nanoimaging experiments with solid density, or in direct observation of the spatial distribution of gas density. In addition, it is absorbed in the surface, in a layer of about 100-500 nm, which allows the material to be modified in a very thin surface layer, without changing its properties in the entire volume, in experiments related to micro- and nano-machining of materials, or to study the properties of these materials in near-edge X-ray absorption fine structure, e.g. for determining chemical composition using NEXAFS spectroscopy or atomic structure using EXAFS. In addition, it allows the generation of large doses of absorbed radiation in radiobiological experiments, or allow for multilayer structure determination with nm accuracy. A very brief overview of such experiments will be presented.
The Evolution of Moore’s Law and Opportunities for the Use of X-ray Systems to Analyze Advanced Semiconductor Packages
Authors: Gregorich Thomas , Ruoff Johannes
Published: January 2021

Moore’s Law is not dead but it is changing and as a result higher-density package interconnects are needed. We will explain the challenges creating these interconnects, how X-ray could fill the inspection and metrology gaps, and overview the requirements.
Propensity rules and interference effects in laser-assisted photoionization of helium and neon
Authors: Bertolino Mattias , Busto David , Zapata Felipe , Dahlström Jan Marcus
Published: January 2021

Angle-resolved electrons from laser-assisted photoionization from atoms are simulated using Time-Dependent Configuration-Interaction Singles. The distributions are interpreted using a propensity rule for transitions in the continuum.
Generating Relativistic Intensities via Staged Pulse Compression in Dielectric Media
Authors: Stanfield M. , Allison H. , Beier N. F. , Hakimi S. , Hussein A. E. , Dollar F.
Published: January 2021

We demonstrate staging of self phase modulation in thin dielectric plates to produce a cost effective means of generating relativistically intense pulses. This new scheme has low loss and maintains focusability.
Enhancing Laser-driven MeV Electron and Proton Spectra with Pseudo-Shaped Short Pulses
Authors: Mariscal Derek , Kim Joohwan , Kemp Andreas , Wilks Scott , Scott Graeme , Simpson Raspberry , Grace Elizabeth , Cochran Ginevra , Park Jaebum , Ma Tammy
Published: January 2021

1. Introduction One of the most studied short-pulse laser-driven particle acceleration schemes is proton generation via the target-normal sheath-acceleration[1] mechanism, where hundreds of experiments[2] have been performed at facilities worldwide. This acceleration mechanism relies on the production of MeV energy electrons from the laser interaction with the target in order to produce 10’s of MeV proton energies. To date, most short-pulse experiments have been performed with single Gaussian-like pulses that are often not well characterized in terms of pulse-length and time-dependent intensity. This is in contrast to nanosecond-scale laser pulses that utilize pulse shaping technique to deliver precise pulse shapes for manipulating time-dependent physics. Such pulse shaping has allowed access to novel physics such as in Inertial Confinement Fusion (ICF) [3] and Equation of State (EOS) [4] experiments. It has similarly allowed for increased efficiency of laser-driven x-ray [5] and particle (proton or neutron) sources [6]. Multiple methods for generating custom pulse shapes at the sub-picosecond level already exist but are rarely employed for high-intensity laser-driven experiments. These methods include combining separate short-pulse beams, splitting and recombining single pulses, interferometric methods [7], or spectral shaping [8]. A limited number of experiments with some form of pulse shaping for high-intensity lasers have shown significant spectral enhancements to secondary sources such as MeV proton beams[9], implying that controlled manipulation of time-dependent particle acceleration physics is possible at the fs to ps level.
Noise-like pulse generation using mode-locked thuliumdoped fiber laser with nonlinear amplifying loop mirror
Authors: Michalska Maria , Grzes Pawel , Swiderski Jacek
Published: January 2021

We investigate a noise-like pulse (NLP) generation in an all-PM-thulium-doped fiber laser. An NLP with a coherence spike width of 232 fs was generated at 1993.6 nm with a 3-dB bandwidth of 32.6 nm.
Plasma Prompts Generation of High-Efficiency Phase-Matched Dispersive Wave in Gas-Filled Hollow-Core PCFs
Authors: Chen Yifei , Huang Zhiyuan , Yu Fei , Wu Dakun , Wang Ding , Leng Yuxin , Xu Zhizhan
Published: January 2021

High-efficiency phase-matched dispersive wave emission is demonstrated in a 25-cm-long He-filled fiber through plasma-driven blueshifting soliton, which can generate compact ultrafast light sources in different spectral regions by a designed fiber geometry.
Average power and pulse energy scalability of thin-rod and thin-tapered-rod Yb:YAG amplifiers
Authors: Kuznetsov Ivan , Chizhov Sergey , Palashov Oleg
Published: January 2021

80W average power with substantial beam quality degradation and 8mJ pulse energy on the optical breakdown limit is achieved from the thin-rod Yb:YAG amplifier. The tapered-rod geometry is proposed to scale both parameters.
Switchable Nano Hybrids: High Intensity Photonic Interactions Between Plasmons and Organic molecules
Authors: Gambhir Kaweri , Sharma Parag , Mehrotra Ranjana
Published: January 2021

With an aim to circumvent intrinsic material bottleneck limitations of all optical switching this work presents a detailed experimental investigation of morphology directed photoinduced intermolecular interactions between an organic fluorophore and four distinct gold nanoshapes.
Tens-of-μJ-level, 20-picosecond, Narrowband Difference-Frequency Generation at 4.6, 5.4, 7.5, 9.2 μm in LiGaS2 and LiGaSe2 at Nd:YAG Laser Pumping and Raman Seeding
Authors: Jelínek M. , Smetanin S. N. , Kurus' A.F. , Isaenko L.I. , Vedenyapin V.N. , Lobanov S.I. , Kubeček V.
Published: January 2021

Tens-of-µJ-level, narrowband difference-frequency generation at discrete wavelengths of 4.6, 5.4, 7.5, and 9.2 µm in LiGaS2 or LiGaSe2 crystals under 20 ps Nd:YAG laser pumping and various crystalline (CaCO3, BaWO4, diamond) Raman laser seeding is presented.
Coherent Thomson Backscattering: Prospects of Compact X-ray Laser
Authors: Tishchenko A.A. , Feshchenko A.M.
Published: January 2021

We have constructed a theory for X-ray source based on Thomson inverse scattering from nano-modulated electron beams. In coherent mode form factor is proved to lead to a sharp increase in intensity, with factor 10^4.
Few-cycle Er Fiber Comb with MW Peak Power
Authors: Lee Kevin F. , Zhou Gengji , Schunemann Peter G. , Jiang Jie , Fermann M. E.
Published: January 2021

We compress a 5 W, 65 fs Er fiber frequency comb to 3 cycles and MW peak power. We show generation of 1 mW of two-octave wide midinfrared.
Ultrafast Thin-Disk based CPA System with >.1kW Output Power and <.500 fs Pulse Duration
Authors: Wandt Christoph , Herkommer Clemens , Jung Robert , Klingebiel Sandro , Krötz Peter , Prinz Stephan , Rampp Michael , Teisset Catherine Y. , Michel Knut , Metzger Thomas
Published: January 2021

A thin-disk based CPA system with a maximum compressed pulse energy of 206 mJ at a repetition rate of 5 kHz and output powers close to 2 kW at 20 kHz is presented. Spectral amplitude shaping led to pulse durations of < 500 fs at 206 mJ.
High Precision Characterization of the Kilojoule Multi-ps Advanced Radiographic Capability
Authors: Alessi David A. , Prantil Matthew A. , Herriot Sandrine I. , Hermann Mark R. , Heebner John E. , Williams Wade H. , Lanier Tom , Widmayer Clifford , Kalantar Daniel H. , Bowers Mark W. , Pelz Lawrence J. , Cabral John , Shaw Michael J. , Di Nicola Jean-Michel G. , Sigurdsson Ron , LaFortune Kai , Hamamoto Matthew Y. , Lawson Janice K. , Lowe-Webb Roger R. , Martinez David , Haefner Constantin , Crane John K. , Homoelle Doug , Barnes Adrian , Paul Mitanu , Wegner Paul J.
Published: January 2021

ARC is a kilojoule petawatt-class laser system which generates high energy x-ray and particle sources for radiography of experiments on the National Ignition Facility. We present recent progress on laser performance measurements and system modeling.
Post-compression of picosecond pulses to four optical cycles
Authors: Balla Prannay , Wahid Ammar Bin , Sytcevich Ivan , Guo Chen , Viotti Anne-Lise , Silletti Laura , Cartella Andrea , Alisauskas Skirmantas , Tavakol Hamed , Grosse-Wortmann Uwe , Schönberg Arthur , Seidel Marcus , Manschwetus Bastian , Lang Tino , Trabattoni Andrea , Calegari Francesca , Couairon Arnaud , L’Huillier Anne , Arnold Cord L. , Hartl Ingmar , Heyl Christoph M.
Published: January 2021

We report post-compression of 1.2 ps pulses into the few-cycle regime via multi-pass spectral broadening. We achieve compression factors of 40 in single and 93 in a dual stage scheme using a compact setup.
Acceleration of quasi mono-energetic electron bunches to ~15 MeV using mJ, few-cycle laser pulses
Authors: Le M. , Salehi F. , Railing L. , Pascale L. , Milchberg H. M.
Published: January 2021

We demonstrate acceleration of quasi mono-energetic electron bunches up to ~15 MeV at 1kHz repetition rate with > pC charge per bunch while using <3mJ laser pulse energy.
Deep Learning for Laser-driven Science: An Introduction For Practitioners
Authors: Spears Brian K.
Published: January 2021

We present an introduction to deep learning for the high-brightness source community, covering methods and examples relevant to computational and experimental investigation. We focus on helping investigators select tools to accelerate entry into deep-learning-augmented research.
Reconfigurable electromagnetically induced transparency metamaterial simultaneously coupled with the incident electric and magnetic fields
Authors: Li Fenying , Mao Mingyu , Zhang Tao , Chen Quanfang , Li Haiming , Zhang Haifeng
Published: January 2021

In this paper, an electromagnetically induced transparency metamaterial simultaneously coupled with the incident electric and magnetic fields is designed and presented theoretically, whereas its reconfigurability, slow-wave effect, low-loss, and polarization insensitivity are analyzed and discussed principally. Based on the tunable solid-state plasma, there is a transmission peak with a 92.06% transmission at 0.544 THz in State 1 and a transmission peak with a 92.84% transmission at 0.7535 THz in State 2, thus achieving a frequency shift of 0.2085 THz. The maximum group delay, group index, and delay-bandwidth product in State 1 or 2, which are 723.7 ps or 494.7 ps, 1024.1 or 700.1, and 48.5 or 36.1, respectively, and the excellent slow-wave effects are discussed. In addition, the low-loss and polarization insensitivity are realized by rotating the split-ring resonators 180° and twisting the planar structure 90°. Considering the unique features of the designed metamaterial, it can be extensively applied to slow-light devices, communication, sensors, and nonlinear devices.
Measuring the sensitivity to optical feedback of single-frequency high-power laser diodes
Authors: Christensen Mathias , Zink Christof , Jamal Muhammad Tahir , Hansen Anders Kragh , Jensen Ole Bjarlin , Sumpf Bernd
Published: January 2021

Laser diodes, in general, are sensitive to optical feedback, especially with regard to maintaining single-frequency operation. Until now, however, the feedback sensitivity of high-power devices such as single-frequency distributed Bragg reflector (DBR) tapered laser diodes has not been investigated in quantitative detail. In this paper, we analyze the impact of very weak optical feedback between

−

105

d
B

and

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40

d
B

on a high-power DBR tapered laser diode. The measurement setup is validated using a typical DFB laser diode. The results are in good agreement with the theory at low-feedback levels.
Organic polymers classification using QCL spectroscopy
Authors: Pazmino-Betancourth Mauro , Ochoa-Gutierrez Victor , Childs David
Published: January 2021

We present preliminary results for a methodology to classify different consumer plastics using mid infrared spectroscopy with an external cavity quantum cascade laser (9.09 – 10.52 µm) for potential applications on microplastics identification in ecosystems.
Frequency noise of Interband Cascade Lasers
Authors: de Cumis Mario Siciliani , Borri Simone , Insero Giacomo , Viciani Silvia , D’Amato Francesco , De Natale Paolo
Published: January 2021

In the mid-infrared (3-6 µm), Interband Cascade Lasers are emerging sources due to their compactness and low-power consumption for high-precision spectroscopy. We investigated frequency noise and linewidth, and show preliminary results of their frequency stabilization.
Long Wavelength Mid-Infrared Supercontinuum Source
Authors: Woyessa Getinet , Dasa Manoj K. , Kwarkye Kyei , Petersen Christian R. , Sidharthan Raghuraman , Chen Shaoxiang , Yoo Seongwoo , Bang Ole
Published: January 2021

We demonstrate a 3 MHz supercontinuum source spanning 1.46 -10.46 μm with 86.6 mW average power. The source is compact and portable, which promises extensive applications in mid infrared spectroscopy and imaging.
High-power Far-infrared Off-axis Parametric Oscillator
Authors: Wu Ming-Hsiung , Lin Yan-Jou , To Bao-Dong , Chiu Yu-Chung , Huang Yen-Chieh
Published: January 2021

We report tunable narrow-line high-power far-infrared radiation between 3-6 THz from off-axis parametric oscillators using lithium niobate and KTP as gain crystals. We measured tens of kW power at 5.7 THz in an ~80 ps width.
5 Terawatt diode-pumped laser for mJ-level THz generation
Authors: Brisset J.-G. , Durand M. , Gontier E. , Saci A. , Sevillano P. , Gavory B. , Courjaud A.
Published: January 2021

We report the development of a compact diode-pumped Terawatt laser dedicated to intense mJ-level Terahertz generation. It delivers 220mJ at 50Hz with 415fs pulse duration and a Strehl ratio exceeding 0,98.
Gapless High-Resolution Dual Comb Spectroscopy with Current-Tuned Quantum Cascade Lasers
Authors: Gianella Michele , Nataraj Akshay , Tuzson Béla , Hugi Andreas , Faist Jérôme , Emmenegger Lukas
Published: January 2021

We measured gapless, high-resolution absorption spectra spanning 55Hz cm-1 by simultaneous current-modulation of two quantum cascade laser frequency combs. Detector noise limited spectra were obtained in as little as 10 ms with a resolution of a few MHz.
Growth of quasi-phase matched ZnSe for mid-IR frequency conversion
Authors: Schunemann Peter G.
Published: January 2021

Unseeded growth of high purity ZnSe single crystals (up to one cubic centimeter) by chemical and physical vapor transport was achieved. Orientation-patterned GaAs templates were designed and grown for seeded growth of quasi-phase matched ZnSe.
Effective Nonlinearity of Trigonal Crystals of Symmetry Class 3 on the Example of the Non-Oxide BaGa2GeSе6
Authors: Miyata Kentaro , Kato Kiyoshi , Badikov Valeriy V. , Panyutin Vladimir L. , Wang Li , Mitin Konstantin V. , Petrov Valentin
Published: January 2021

We determine the optimum propagation direction for maximum effective nonlinearity in the recently developed BaGa2GeSe6 nonlinear crystal based on magnitude and relative sign of its nonlinear coefficients with proper octant assignment involving the axis sense.
Laser Performance of the Fe2+:CdTe Single Crystal at Room Temperature
Authors: Leonov Stanislav O. , Frolov Mikhail P. , Korostelin Yurii V. , Skasyrsky Yan K. , Kozlovsky Vladimir I.
Published: January 2021

We demonstrate the laser performance of a Fe2+:CdTe single crystal pumped by a Q-switched Er:YAG laser at room temperature. The Fe:CdTe laser produced 2 mJ of output energy at the central wavelength of 5.55 µm with slope efficiency of 16% with respect to absorbed pump energy. The tunability was demonstrated in the wavelength range from 5.1 to 6.3 µm. The lifetime of the upper laser level was estimated to be of 530 ns at room temperature.
Tm, Ho:GGAG Disordered Garnet Crystal for Tunable 2.1 µm Cryogenically Cooled Laser
Authors: Kratochvíl Jan , Boháček Pavel , Šulc Jan , Němec Michal , Fibrich Martin , Jelínková Helena , Trunda Bohumil , Havlák Lubomír , Jurek Karel , Nikl Martin
Published: January 2021

Cryogenic conditions were used to improve efficiency up to 48 % and power to 5.5 W of diode-pumped tunable laser based on disordered Tm, Ho: GGAG crystal. Wavelength-tuning range of 1996–2115 nm was achieved.
One-shot phase retrieval method for interferometry using a hypercolumns convolutional neural network
Authors: Zhao Zhuo , Li Bing , Lu Jiasheng , Kang Xiaoqin , Liu Tongkun
Published: January 2021

In three dimensional profilometry, phase retrieval technique plays a key role in signal processing stage. Fringe images need to be transformed into phase information to obtain the measurement result. In this paper, a new phase retrieval method based on deep learning technique is proposed for interferometry. Different from conventional multi-step phase shift methods, phase information can be extracted from only a single frame of an interferogram by this method. Here, the phase retrieval task is regarded as a regression problem and a hypercolumns convolutional neural network is constructed to solve it. Firstly, functions and each component of the network model are introduced in details; Then, four different mathematical functions are adopted to generate the training dataset; training and validation strategies are also designed subsequently; Finally, optimization processing is performed to eliminate local data defects in initial results with the help of polynomial fitting. In addition, hardware platform based on point diffraction interferometer is fabricated to support this method. Concluded from the experiment section, the proposed method possesses a desirable performance in terms of phase retrieval, denoising and time efficiency.
Rapid parameter determination of discrete damped sinusoidal oscillations
Authors: Visschers Jim C. , Wilson Emma , Conneely Thomas , Mudrov Andrey , Bougas Lykourgos
Published: January 2021

We present different computational approaches for the rapid extraction of the signal parameters of discretely sampled damped sinusoidal signals. We compare time- and frequency-domain-based computational approaches in terms of their accuracy and precision and computational time required in estimating the frequencies of such signals, and observe a general trade-off between precision and speed. Our motivation is precise and rapid analysis of damped sinusoidal signals as these become relevant in view of the recent experimental developments in cavity-enhanced polarimetry and ellipsometry, where the relevant time scales and frequencies are typically within the ∼1 − 10 µs and ∼1 − 100 MHz ranges, respectively. In such experimental efforts, single-shot analysis with high accuracy and precision becomes important when developing experiments that study dynamical effects and/or when developing portable instrumentations. Our results suggest that online, running-fashion, microsecond-resolved analysis of polarimetric/ellipsometric measurements with fractional uncertainties at the 10−6 levels, is possible, and using a proof-of-principle experimental demonstration we show that using a frequency-based analysis approach we can monitor and analyze signals at kHz rates and accurately detect signal changes at microsecond time-scales.