Search results for "Responsivity"

Responsivity measurements of N-on-P and P-on-N silicon photomultipliers in the continuous wave regime

2013

We report the electrical and optical comparison, in continuous wave regime, of two novel classes of silicon photomultipliers (SiPMs) fabricated in planar technology on silicon P-type and N-type substrate respectively. Responsivity measurements have been performed with an incident optical power from tenths of picowatts to hundreds of nanowatts and on a broad spectrum, ranging from ultraviolet to near infrared (340-820 nm). For both classes of investigated SiPMs, responsivity shows flat response versus the optical incident power, when a preset overvoltage and wavelength is applied . More in detail, this linear behavior extends up to about 10 nW for lower overvoltages, while a shrink is observ…

Measurements of Silicon Photomultipliers Responsivity in Continuous Wave

2012

N-on-P and P-on-N Silicon Photomultipliers: Responsivity comparison in the continuous wave regime

2013

We report on the electrical and optical comparison, in continuous wave regime, of two novel classes of silicon photomultipliers fabricated in planar technology on silicon P-type and Ntype substrate respectively. A physical explanation of the experimental results is provided.

Measurements of Silicon Photomultipliers Responsivity

2012

We present some results on the optical characterization of Silicon Photomultipliers designed for medical imaging applications. In particular we will discuss our responsivity measurements performed with very low incident optical power and on a broad spectrum

Measurements of Silicon Photomultipliers Responsivity in Continuous Wave Regime

2013

We report on the electrical and optical characterization, in continuous wave regime, of a novel class of silicon photomultipliers fabricated in standard planar technology on a silicon p-type substrate. Responsivity measurements, performed with an incident optical power down to tenths of picowatts, at different reverse bias voltages and on a broad (340–820 nm) spectrum, will be shown and discussed. The device temperature was monitored, allowing us to give a physical interpretation of the measurements. The obtained results demonstrate that such novel silicon photomultipliers are suitable as sensitive power meters for low photon fluxes.

Solar blind detectors based on AlGaN grown on sapphire

2005

Solar blind detectors have been fabricated based on AlGaN heterostructures grown on sapphire by molecular beam epitaxy or chemical vapour deposition. MSM and Schottky detectors were investigated. High performance devices have been obtained thanks to an optimization of the material crystalline quality (including the suppression of cracks) and of the process. We show that the spectral limitations of MSM detectors are dictated by intrinsic phenomena that are analysed in details while the responsivity and detectivity also depends on the technological process with a special emphasis on the geometry of finger and contact pads. One and two dimensional arrays have been fabricated and preliminary re…

Transkraniaalisen tasavirtastimulaation vaikutukset erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin

2017

Transkraniaalisella tasavirtastimulaatiolla (tDCS) tarkoitetaan menetelmää, jossa johdetaan heikkoa sähkövirtaa aivokudosten läpi elektrodilta toiselle. Tutkimusten mukaan tDCS:lla näyttäisi olevan monenlaisia kliinisiä ja kognitiivisia vaikutuksia aina masennuksen hoidosta työmuistin parantamiseen. Tulokset ovat kuitenkin monin paikoin varsin ristiriitaisia, eikä stimulaation tarkoista vaikutusmekanismeistakaan olla päästy varmuuteen. Tässä tutkimuksessa halusimme tutkia kokeellisesti tDCS:n vaikutuksia erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin silmäniskuehdollistumisen avulla. Kokeeseen osallistui 39 iältään 18-29-vuotiasta koehenkilöä. Tutkittavat jaettiin kahte…

Electro-optical characterization of new classes of Silicon Carbide UV photodetectors

2014

In this paper, we present the fabrication process steps and the characterization of 4H-SiC vertical Schottky UV detectors, where interdigitated strips, acting as top metal contacts, have been realized in $\hbox{Ni}_{2}\hbox{Si}$ . These devices exploit the pinch-off surface effect. $I$ – $V$ and $C$ – $V$ characteristics, as functions of temperature, were measured in dark conditions. In addition, we have carried out responsivity measurements, for wavelengths ranging from 200 to 400 nm, at varying package temperature and applied reverse bias. A comparison among devices having different strip pitch sizes has been performed, thus finding out that the 10- $\mu\hbox{m}$ pitch class demonstrates …

First-in-man permanent laparoscopic fixation free obliteration of inguinal hernia defect with the 3D dynamic responsive implant ProFlor-E®. Case repo…

2020

Abstract Introduction In the case of inguinal hernia recurrence after primary anterior repair, international guidelines strongly suggest a posterior laparoscopic approach. The 3D dynamic-responsive prosthesis for inguinal hernia repair ProFlor-E® has recently been introduced to the market. The present report describes the results of the first-in-man laparoscopic inguinal hernia repair carried out with ProFlor-E®. Presentation of case A 71-year-old male Caucasian presented with recurrent inguinal hernia after primary anterior repair. A fixation free TAPP procedure with ProFlor-E® was planned. Implant delivery and placement to obliterate the defect was quick and safe. Postoperatively, startin…

THE SILICON PHOTOMULTIPLIER:AN IN-DEPTH ANALYSIS IN THE CONTINUOUS WAVE REGIME

2014

The Silicon Photomultiplier (SiPM) is a novel solid state photon counting detector consisting of a parallel array of avalanche photodiodes biased beyond their breakdown voltage. It has known a fast development in the last few years as a possible alternative to vacuum photomultiplier tubes (PMTs) and conventional avalanche photodiodes (APDs). Indeed, current research in photodetectors is directed toward an increasing miniaturization of the pixel size, thus both improving the spatial resolution and reducing the device dimensions. SiPMs show high photon detection efficiency in the visible and near infrared range, low power consumption, high gain, ruggedness, compact size, excellent single-phot…