Search results for "SiPM"
showing 10 items of 36 documents
FPGA based digital lock-in amplifier for fNIRS systems
2018
Lock-In Amplifiers (LIA) represent a powerful technique helping to improve signals detectability when low signal to noise ratios are experienced. Continuous Wave functional Near Infrared Spectroscopy (CW-fNIRS) systems for e-health applications usually suffer of poor detection due to the presence of strong attenuations of the optical recovering path and therefore small signals are severely dipped in a high noise floor. In this work a digital LIA system, implemented on a Zynq® Field Programmable Gate Array (FPGA), has been designed and tested to verify the quality of the developed solution, when applied in fNIRS systems. Experimental results have shown the goodness of the proposed solutions.
CY5 fluorescence measured with silicon photomultipliers
2014
This paper presents an efficient optical biosensor set up for a low-level light detection, using fluorescent dyes and a novel Si-based detector. Fluorescence emitted by a traditional fluorophore, CY5, widely used as optical label in DNA microarrays, was detected using a 25 pixels Silicon photomultiplier (SiPM), a device formed by avalanche diodes operating in Geiger mode, in parallel connections. We measured the fluorescence current in different deposition (fluorophore concentration; solvent; salt concentration) and operation (angle of analysis, optical laser power, device gain) conditions. The characterization of DNA samples labeled with CY5 is also reported to demonstrate the detector pot…
SiPM as miniaturised optical biosensor for DNA-microarray applications
2015
A miniaturized optical biosensor for low-level fluorescence emitted by DNA strands labelled with CY5 is showed. Aim of this work is to demonstrate that a Si-based photodetector, having a low noise and a high sensitivity, can replace traditional detection systems in DNA-microarray applications. The photodetector used is a photomultiplier (SiPM), with 25 pixels. It exhibits a higher sensitivity than commercial optical readers and we experimentally found a detection limit for spotted dried samples of ∼1 nM. We measured the fluorescence signal in different operating conditions (angle of analysis, fluorophores concentrations, solution volumes and support). Once fixed the angle of analysis, for s…
Exploring FPGA‐Based Lock‐In Techniques for Brain Monitoring Applications
2017
Functional near‐infrared spectroscopy (fNIRS) systems for e‐health applications usually suffer from poor signal detection, mainly due to a low end‐to‐end signal‐to‐noise ratio of the electronics chain. Lock‐in amplifiers (LIA) historically represent a powerful technique helping to improve performance in such circumstances. In this work a digital LIA system, based on a Zynq® field programmable gate array (FPGA) has been designed and implemented, in an attempt to explore if this technique might improve fNIRS system performance. More broadly, FPGA‐based solution flexibility has been investigated, with particular emphasis applied to digital filter parameters, needed in the digital LIA, and its …
A LiDAR Prototype with Silicon Photomultiplier and MEMS Mirrors
2018
In this paper, we present a low cost prototype of a Time-Of-Flight (TOF) LiDAR system, employing a SiPM as photo detector and MEMS mirrors in order to steer the nanosecond pulsed optical beam with a scanning angle of +/-6°. Preliminary TOF measurements have been performed both indoor and outdoor to test the limits of the system.
TOF LiDAR with SiPM technology
2016
LiDAR (Light Detection And Ranging) systems measures the distance from the sensor to the target by determining the time between the release of the laser pulse to the receiving of the backscattered pulse. The interest in LiDAR technology has exploded in recent years since the applications are numerous. Here, we would highlight the Advanced Driver Assistance Systems (ADAS) and for rendezvous & docking operations between spacecraft. We built two LiDAR systems differing for the detector: a Silicon Photomultiplier (SiPM) and an Avalanche Photodiode (APD). The advantages of the SiPM approach has been extensively discussed in [1]. The comparison between these systems has been performed in terms of…
Comparison in terms of TOF measurements between APD and SiPM for LiDAR applications
2016
We present an experimental comparison of two LiDAR systems, employing the SiPM and the APD as photodetectors, in terms of TOF measurements differing for the distance of the target and at different intensities of ambient light. The use of the APD represents the conventional approach, while the implementation of the SiPM is innovative. The performed measurements achieved very promising results, thus demonstrating the effectiveness of our LiDAR based on SiPM.
Signal to Noise Ratio of Silicon Photomultipliers measured in the Continuous Wave Regime
2014
We performed a Signal to Noise Ratio characterization, in the continuous wave regime, at different bias voltages, frequencies and temperatures, on a novel class of silicon photomultipliers fabricated in planar technology on silicon p-type substrate. Signal to Noise Ratio has been measured as the ratio of the photogenerated current, filtered and averaged by a lock-in amplifier, and the Root Mean Square deviation of the overall current flowing to the device. The measured noise takes into account the shot noise, resulting from the photocurrent and the dark current. We have also performed a comparison between our SiPMs and a photomultiplier tube in terms of Signal to Noise Ratio, as a function …
Detector characterization and first coincidence tests of a Compton telescope based on LaBr3 crystals and SiPMs
2011
International audience; A Compton telescope for dose monitoring in hadron therapy consisting of several layers of continuous LaBr3 crystals coupled to silicon photomultiplier (SiPM) arrays is under development within the ENVISION project. In order to test the possibility of employing such detectors for the telescope, a detector head consisting of a continuous 16 mm×18 mm×5 mm LaBr3 crystal coupled to a SiPM array has been assembled and characterized, employing the SPIROC1 ASIC as readout electronics. The best energy resolution obtained at 511 keV is 6.5% FWHM and the timing resolution is 3.1 ns FWHM. A position determination method for continuous crystals is being tested, with promising res…
High resolution detectors based on continuous crystals and SiPMs for small animal PET
2012
International audience; Sensitivity and spatial resolution are the two main factors to maximize in emission imaging. The improvement of one factor deteriorates the other with pixelated crystals. In this work we combine SiPM matrices with monolithic crystals, using an accurate γ-ray interaction position determination algorithm that provides depth of interaction. Continuous crystals provide higher sensitivity than pixelated crystals, while an accurate interaction position determination does not degrade the spatial resolution. Monte Carlo simulations and experimental data show good agreement both demonstrating sub-millimetre intrinsic spatial resolution. A system consisting in two rotating det…