In recent years, there has been a growing interest in the use of single-photon avalanche diode (SPAD) optical wireless communication (OWC). The SPAD operates Geiger mode and can act as photon counting receiver obviating need for transimpedance amplifier. Although provide higher sensitivity compared to traditional linear photodetectors, it suffers from dead-time-induced nonlinearity. To improve ...

Abstract This paper presents a digitally controlled charge pump (DCP) to supply high voltages, while ensuring temperature and load current independence of excess bias in cameras based on avalanche photodiodes. This is achieved through a single-photon avalanche diode (SPAD) based monitoring mechanism that continuously reconfigures the DCP using a feedback loop to compensate breakdown voltage var...

This contribute describes the design and preliminary characterization of a 16x16-pixel array based on Single Photon Avalanche Diodes (SPADs), fabricated in a standard high-voltage 0.35μm CMOS technology, and aimed at the analysis of fluorescence phenomena. Each pixel integrates a SPAD combined with an active quenching circuit and a voltage comparator for the digital conversion of the avalanche ...

e report the design and characterisation of a 32x32 time to digital (TDC) converter plus single photon avalanche diode (SPAD) pixel array implemented in a 130nm imaging process. Based on a gated ring oscillator approach, the 10 bit, 50μm pitch TDC array exhibits a minimum time resolution of 50ps, with accuracy of ±0.5 LSB DNL and 2.4 LSB INL. Process, voltage and temperature compensation (PVT) ...

Nitrogen (N) and Phosphorus (P) deficiency is a major yield limiting factor across the globe their proper management plays vital role in optimizing crop yield. This field experiment was conducted to assess impact of soil plant nitrogen N P ratio on growth wheat (Triticum aestivum L.) alkaline calcareous soil. The study consisted various levels (0, 40, 80, 160 kg ha−1 as urea) phosphorus 30, 60,...

Single-photon avalanche diode (SPAD) exploitation in high-flux applications is often hindered by the trade-off between SPAD dead-time and afterpulsing probability. In this paper, we present architecture experimental characterization of two chips including a novel sensing, readout scheme designed to minimize (1.78 ns 0.93 respectively) probability (0.14% maximum). We have coupled with hig...

Leaf chlorophyll content is crucial for monitoring plant growth and photosynthetic capacity. The Soil Plant Analysis Development (SPAD) values are widely utilized as a relative index in ecological agricultural surveys vegetation remote sensing applications. Multi-spectral cameras cost-effective alternative to hyperspectral monitoring. However, the limited spectral bands of multi-spectral restri...

Single-molecule Förster resonance energy transfer (smFRET) is a powerful tool for extracting distance information between two fluorophores (a donor and acceptor dye) on a nanometer scale. This method is commonly used to monitor binding interactions or intra- and intermolecular conformations in biomolecules freely diffusing through a focal volume or immobilized on a surface. The diffusing geomet...