We present our third prototype sensor and a localization method for Automated Guided Vehicles (AGVs), for which small imaging LIght Detection and Ranging (LIDAR) and fusion-based localization are fundamentally important. Our small imaging LIDAR, named the Single-Photon Avalanche Diode (SPAD) LIDAR, uses a time-of-flight method and SPAD arrays. A SPAD is a highly sensitive photodetector capable ...

The appearance of miniaturized single-photon detectors has enabled massively parallel conversion of photons to digital signals that can be readily processed and/or transported with negligible losses. As a consequence, a new class of imaging sensors is emerging, known collectively as all-digital image sensors, for detection and processing of ultra-fast and complex photonic events, often present ...

A Soil-Plant Analysis Development (SPAD) chlorophyll meter can be used as a simple tool for evaluating N concentration of the leaf and investigating the combined effects of nitrogen rate and leaf age on N distribution. We conducted experiments in a paddy field over two consecutive years (2008-2009) using rice plants treated with six different N application levels. N distribution pattern was det...

Quantum random number generators (QRNGs) are a burgeoning technology used for variety of applications, including modern security and encryption systems. Typical methods exploit an entropy source combined with extraction or bit generation circuit in order to produce string. In integrated designs, there is often little modeling analytical description the source, extraction, post-processing provid...

One of the key hazardous events in railways is signals passed at danger (SPAD). SPAD events are relatively common, most with minor consequence. However, SPAD events with catastrophic consequences happen sufficiently often to be a concern within the rail industry. A SPAD event is a precursor to a train collision or derailment; hence there is a strong focus on measuring and reducing their frequen...

Reduced levels of leaf chlorophyll content per unit leaf area in crops may be of advantage in the search for higher yields. Possible reasons include better light distribution in the crop canopy and less photochemical damage to leaves absorbing more light energy than required for maximum photosynthesis. Reduced chlorophyll may also reduce the heat load at the top of canopy, reducing water requir...

Rice leaves display lateral asymmetry around the midrib, and the narrow side exhibits higher leaf area-based nitrogen concentration (Na) and soil plant analysis development (SPAD) values than the wider side. However, the difference in the relationship between the SPAD of each side and Na of the corresponding lateral half, and the optimal position along the leaf blade for SPAD measurements are n...

A highly accurate method for the determination of the detection efficiency of a silicon single-photon avalanche diode (Si-SPAD) is presented. This method is based on the comparison of the detected count rate of the Si-SPAD compared to the photon rate determined from a calibrated silicon diode using a modified attenuator technique, in which the total attenuation is measured in two attenuation st...

Advances in SPAD sensor technology have recently yielded a >10kfps, 320x240 resolution imager [1] that can be operated as a Quanta Image Sensor (QIS) [2]. This device (labelled SPCImager) thus combines the high speed and sensitivity afforded by SPAD devices with the negligible readout noise and logarithmic compression of QIS. These attributes open the door to a number of potential applications ...

Single-photon avalanche diode (SPAD) detector arrays generally suffer from having a low fill-factor, in which the photo-sensitive area of each pixel is small compared to the overall area of the pixel. This paper describes the integration of different configurations of high efficiency diffractive optical microlens arrays onto a 32 × 32 SPAD array, fabricated using a 0.35 µm CMOS technology proce...