Low Noise and High Photodetection Probability SPAD in 180 nm Standard CMOS Technology

A square shaped, low noise and high photo-response single photon avalanche diode suitable for circuit integration, implemented in a standard CMOS 180 nm high voltage technology, is presented. In this work, a p+ to shallow n-well junction was engineered with a very smooth electric field profile guard ring to attain a photo detection probability peak higher than 50% with a median dark count rate lower than 2 Hz/μm2 when operated at an excess bias of 4 V. The reported timing jitter full width at half maximum is below 300 ps for 640 nm laser pulses

A 64x64 SPAD array for portable colorimetric sensing, fluorescence and X-ray imaging

We present the design and application of a 64x64 pixel SPAD array to portable colorimetric sensing, and fluorescence and x-ray imaging. The device was fabricated on an unmodified 180 nm CMOS process and is based on a square p+/n active junction SPAD geometry suitable for detecting green fluorescence emission. The stand-alone SPAD shows a photodetection probability greater than 60% at 5 V excess bias, with a dark count rate of less than 4 cps/µm2 and sub-ns timing jitter performance. It has a global shutter with an in-pixel 8-bit counter; four 5-bit decoders and two 64-to-1 multiplexer blocks allow the data to be read-out. The array of sensors was able to detect fluorescence from a fluorescein isothiocyanate (FITC) solution down to a concentration of 900 pM with a SNR of 9.8 dB. A colorimetric assay was performed on top of the sensor array with a limit of quantification of 3.1 µM. X-rays images, using energies ranging from 10 kVp to 100 kVp, of a lead grating mask were acquired without using a scintillation crystal

A Simultaneous Equation Model of Globalization, Corruption, Democracy, Human Development and Social Progress

This study builds a simultaneous equation model that establishes inter-connections among the measures of globalization, measures of democracy, human development, corruption perception index and per capita income, which in turn jointly influence social progress. The model has eleven equations in which the response variables and the predictor variables are log-linearly related. The empirical data used for estimation of the model pertain to the period 2006-2016 for 116 countries distributed over all the continents. The model has been estimated by the conventional Two-Stage Least Squares (2-SLS) and alternatively by a modified 2-SLS in which, at the second stage, Shapley value regression has been used to ameliorate the detrimental effects of collinearity among the predictor variables. It has been found that the modified 2-SLS outperforms the conventional 2-SLS. Empirically, it has been established that globalization, democracy, human development and low level of corruption are reinforcing each other and they together explain social progress quite well

An all-dielectric metasurface polarimeter

The data in this set are organised into the following folders: Figure 2 folder: This contains the data plotted in Figure 2 (a) - (i) of the manuscript. The simulation data are provided in *.mat format and the experimental data is provided in *.asc format. This is the data for the experimental diffraction patterns and finite-difference time-domain (FDTD) simulations for the degenerate polarization states. Figure 3 folder: This contains the data plotted in Figure 3 (a) - (d) of the manuscript. The data is provided in Excel *.xlsx format. This is the data generated from using the intensity of the diffracted spots to extract the Stokes parameters and comparing with analytical Stokes’ values

Terahertz polarimetry with a monolithic metasurface

Data on FDTD simulations of the elemental meta-pillars and collective simulation of the assembled metasurface polarimeter (MSP). Furthermore, experimentally obtained data for each different incident polarisation are deposited including the self-written analysis scripts

A 64x64 SPAD array for portable colorimetric sensing, fluorescence and x-ray imaging

Design and characterization of the designed test Single photon avalanche diode (SPAD) and the 64x64 pixel array based on the test SPAD. The test SPAD performances are compared to the state-of-the-art to prove the effectiveness of the design at low illumination condition. The 64x64 SPAD array performances are characterized and the results of three different applications (colorimetric sensing, fluorescence and x ray imaging) are reported