1,721,029 research outputs found
InGaAs/InP single-photon detector gated at 1.3 GHz with 1.5% afterpulsing
Full text linkWe demonstrate a single-photon detector based on InGaAs/InP single-photon avalanche diodes (SPADs) sinusoidalgated at 1.3 GHz with very low afterpulsing (about 1.5%), high dynamic range (maximum count rate is 650 Mcount/s), high photon detection efficiency (>30% at 1550 nm), low noise (per-gate dark count rate is 2.2 x 10(-5)), and low timing jitter (<70 ps full-width at half-maximum). The SPAD is paired with a "dummy" structure that is biased in antiphase. The sinusoidal gating signals are cancelled by means of a common-cathode configuration and by adjusting the relative amplitude and phase of the signals biasing the two arms. This configuration allows us to adjust the gating frequency from 1 to 1.4 GHz and can be operated also in the so-called gate-free mode, with the gate sine-wave unlocked with respect to the light stimulus, resulting in a free-running equivalent operation of the InGaAs/InP SPAD with about 4% average photon detection efficiency at 1550 nm
Photon counting module based on InGaAs/InP Single-Photon Avalanche Diodes for near-infrared counting up to 1.7 μm
No full textInGaAs/InP Single-Photon Avalanche Diodes (SPADs) have good performance to be successfully employed in many applications that demand single photon detection in the 1 - 1.7 μm wavelength range. However, in order to fully exploit such detectors, they have to be operated in optimized working conditions using dedicated electronics. We present the design and experimental characterization of a high-performance compact detection module able to operate at best InGaAs/InP SPADs. The module includes a pulse generator for gating the detector, a front-end circuit for avalanche sensing, a fast circuitry for detector quenching and resetting and some sub-circuits for signal conditioning. Experimental measurements prove the state-of-the-art performance and its great flexibility to fit the different applications
Fully programmable single-photon detection module for InGaAs/InP single-photon avalanche diodes with clean and sub-nanosecondgating transitions
No full textWe present the design and characterization of a modern near-infrared photon counting module, able to exploit the best performance of InGaAs/InP single-photon avalanche diodes for the detection of fast and faint optical signals up to 1.7 μm. Such instrument is suitable for many applications, thanks to the user-friendly interface and the fully adjustable settings of all operating parameters. We extensively characterized both the electronics and the detector, and we validated such instrument up to 133 MHz gate repetition frequency, for photon-counting and photon-timing applications, with very clean temporal response and excellent timing performance of less than 100 ps
Single-photon counting with InGaAs/InP SPAD
No full textWe present a full-programmable single-photon counting module for the near-infrared wavelength range based on InGaAs/InP Single-Photon Avalanche Diode. It has high detection efficiency (> 25%), low timing jitter (<90 ps) and 133 MHz gate repetition rate
The impact of the COVID-19 pandemic on burnout and mental well-being of healthcare workers at Lago di Garda hospitals, Northern Italy
Full text linkIntroduzione: Gli operatori sanitari esposti all'epidemia da coronavirus Covid-19 soffrono di un affaticamento psicofisico persistente, che può portare ad esaurimento emotivo e a burnout. Questo studio mira ad analizzare i livelli di esaurimento psicofisico dei professionisti della salute, ad esplorare i fattori che causano lo stress lavoro correlato e ad identificare i fattori protettivi nei confronti del malessere psicologico sul posto di lavoro.
Metodi: L’indagine è stata effettuata durante l’estate di 2020, in piena pandemia Covid-19. Un gruppo di 1.191 operatori sanitari (23,1% maschi, 76,9% femmine), operanti negli ospedali di ASST Garda (porzione sudorientale della Provincia di Brescia), è stato invitato a compilare il questionario
quali-quantitativo. L'analisi dei dati è stata realizzata con il metodo misto (QN + QL).
Risultati: È stato individuato un alto livello di affaticamento psicofisico, soprattutto nei reparti Covid-19. È stato riscontrato che i due gruppi di lavoro con 15-19 e 20-24 anni di esperienza, risultavano particolarmente vulnerabili in termini di fatica psicofisica e salute mentale. Dall'analisi qualitativa dei dati sono emersi tre gruppi di fattori che descrivono le principali difficoltà nei reparti ospedalieri e le cause dell’esaurimento psicofisico degli operatori sanitari durante il primo periodo dell’emergenza da Covid-19: fattore lavoro, fattore salute e fattori personali.
Conclusioni: I risultati rilevano che la pandemia da Covid-19 ha influenzato negativamente la salute mentale degli operatori sanitari in stretto contatto con i pazienti, portando ad elevati livelli di stress e stanchezza psicofisica. Le principali cause sono il sovraccarico di lavoro e la paura della contaminazione. Si segnala un’impellente necessità di sostenere gli operatori sanitari e di promuovere il loro benessere psicologico. La politica e i responsabili del settore dovrebbero organizzarre tempestivamente i servizi di supporto psicologico per far fronte alle problematiche emerse dall’indagine.Introduction: Healthcare professionals (HCPs) suffer from persistent psychophysical fatigue after being exposed to the coronavirus pandemic (Covid-19), which can lead to emotional distress and burnout. This study aimed to assess healthcare professional’s psychophysical exhaustion, to explore the factors influencing work-related stress and to identify the protective factors in the workplace. Methods: 1,191 HCPs (23.1% male, 76.9% female), working in hospitals of ASST Garda (Northern Italy), in the first period of full coronavirus pandemic (Covid-19), were asked to complete the self- administered questionnaire. The mixed method (QN + QL) was employed for collecting and analyzing the data.
Results: A high level of psychophysical fatigue was discovered, especially in the Covid wards. It was found that the two senior work groups with 15-19 and 20-24 years of experience, were particularly vulnerable in terms of psychophysical fatigue and mental health. From the qualitative data analysis, three core categories emerged: work, health and personal factors, which described the specific factors, both in terms of main difficulties and factors that induced the HCP's psychophysical exhaustion during the first period of the health emergency.
Conclusions: Our findings suggest that the Covid-19 pandemic has negatively affected mental health of HCPs caring for Covid-19 infected patients, leading to increased levels of stress and burnout, due to work overload and fear of contamination. There is a need to promote psychological well-being and support for healthcare professionals. Policy and sector managers should promptly organize psychological support services to deal with the problems that emerged from the investigation
InGaAs/InP single-photon counting module running up to 133 MHz
No full textWe present new circuital solutions for operating InGaAs/InP SPADs at high speed with very fast avalanche quenching time. A compact wide-band pulse generator (mounted close to the detector) is able to gate the SPAD at a repetition frequency from 200 Hz up to 133 MHz. An adjustable amplitude gate-driver allows to trade-off between photon detection efficiency and dark count rate, while a variable gate-width precisely selects the time interval during which the detector is ON. A fast avalanche-quenching scheme, working on both SPAD's anode and cathode, is able to minimize quenching action to less than 1 ns, thus effectively reducing afterpulsing through a decreased total charge flowing through the junction. We integrated all such circuits into a compact detection module, together with a previouslyreported differential read-out electronics for low time-jitter response. The performance of the overall module is good in many different setting points, thus being able to satisfy a wide variety of applications
Theoretical and experimental investigations into spatial correlations in spontaneous parametric downconversion
No full textTemporal trends of polychlorinated biphenyls serum levels in subjects living in a highly polluted area from 2003 to 2015: a follow-up study
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