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...

We have characterized a new commercial chlorophyll (Chl) and flavonoid (Flav) meter called Dualex 4 Scientific (Dx4). We compared this device to two other Chl meters, the SPAD-502 and the CCM-200. In addition, Dx4 was compared to the leaf-clip Dualex 3 that measures only epidermal Flav. Dx4 is factory-calibrated to provide a linear response to increasing leaf Chl content in units of µg cm(-2), ...

The recent development of 2D arrays of single-photon avalanche diodes (SPAD) has driven the development of applications based on the ability to capture light in motion. Such arrays are composed typically of 32x32 SPAD detectors, each having the ability to detect single photons and measure their time of arrival with a resolution of about 100 ps. Thanks to the single-photon sensitivity and the hi...

A hydroponic experiment carried out to study the effect of five Cd levels on growth and photosynthesis of two tomato cultivars showed that the addition of 0.1 micromol/L Cd induced a slight increase in plant height of Hezuo 903 and the SPAD (the Soil-Plant Analyses Development) value of the 2 cultivars. However, at higher Cd levels, i.e., 1 and 10 micromol/L, root length and volume, plant heigh...

Abstract
 This study was carried out to determine the leaf stoma characteristics and SPAD value of total 18 grape varieties (10 local 8 commercial) grown in Kayseri region. Among ranged from 29.23 (Çekirdeksiz) 42.26 (Kara Burcu), frequency (stoma/mm2) 85.99 Burcu) 136.83 (Tarsus Beyazı). Although there a positive correlation between width length, these parameters did not show statistical ...

Article history: Received 21 May 2017 Received in revised form 19 June 2017 Accepted 9 July 2017 Available online 15 July 2017 Single photon avalanche diode (SPAD) is one of the promising candidates among photodetectors due to its high sensitivity and accuracy. Alongwith the existing custom compound avalanche diodes, SPADs fabricated in CMOS technology have been suggested and studied widely due...

Single-photon avalanche diode (SPAD) imagers typically have a relatively low fill factor, i.e. a low proportion of the pixel's surface is light sensitive, due to in-pixel circuitry. We present a microlens array fabricated on a 128×128 single-photon avalanche diode (SPAD) imager to enhance its sensitivity. The benefits and limitations of these light concentrators are studied for low light imagin...

We report on the development of a doubly weighted Gerchberg-Saxton algorithm (DWGS) to enable generation of uniform beamlet arrays with a spatial light modulator (SLM) for use in multiphoton multifocal imaging applications. The algorithm incorporates the WGS algorithm as well as feedback of fluorescence signals from the sample measured with a single-photon avalanche diode (SPAD) detector array....

A monolithic circuit has been designed for active-quenching and active-reset of single-photon avalanche diodes (SPADs), which operate above the breakdown voltage BD for detecting single photons. To the best of our knowledge, this is the first fully integrated circuit of this kind ever reported. It can operate with any available SPAD device, since it generates pulses high enough to quench detect...