Electrically-pumped GaSb-based vertical-cavity surface-emitting lasers emitting up to 2.63 µm at room temperature are reported. The whole structure was grown monolithically in one run by solid-source molecular beam epitaxy. This heterostructure is composed of two n-doped AlAsSb/GaSb DBRs, a type-I GaInAsSb/AlGaAsSb multi-quantum-well active region and an InAsSb/GaSb tunnel junction. A quasi-CW (1 µs, 5 %) operation obtained for 35 µm-diameter devices with threshold current 85 mA.

This study focuses on the promising use of biospeckle technology to detect water stress in plants, a complex physiological mechanism. involves monitoring temporal activity pattern occurrence within leaf. The effects plants can involve physical and biochemical changes. Some these changes may alter optical scattering properties leaves. present therefore proposes test potential measurement observe evolution different varieties sunflower under stress. An experiment applying controlled with...

This paper is dedicated to the study of electrical and optical properties four different doped 21.5 pairs AlAsSb/GaSb distributed Bragg reflectors lattice-matched GaSb designed for fabrication electrically pumped VCSELs emitting around 2.3 µm. Three doping profiles have been carried out: n-bulk doping, n-delta p-bulk doping. An n-type bulk mirror with step composition at GaSb/AlAsSb interfaces was also tested. The sample sharp exhibited best properties, a voltage drop per pair 25 mV specific...

Room-temperature continuous-wave (CW) operation of GaSb-based monolithic microcavity vertical-cavity surface-emitting lasers operating near 2.3 mum is presented. These devices were composed two n-doped AlAsSb-GaSb Bragg mirrors, a type-I GaInAsSb-AlGaAsSb multiquantum-well active region, and an n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">++</sup> -InAsSb/p -GaSb tunnel junction. CW laser was observed up to 294 K. A threshold current...

Aims: This work aims to study the quality of low cost Digital Surface Models (DSMs) obtained with Unmanned Aerial Vehicle (UAV) images and test whether these DSMs meet common requirements wine industry.Methods results: Experiments were carried out on a 4-ha vineyard located 10 km north Beziers (France). The experimental site presents slope aspect variations representative mechanised commercial vineyards in Languedoc Roussillon. provided by three UAV companies selected for diversity their...

An all-epitaxial monolithic vertical cavity surface emitting laser grown on GaSb substrate is presented. The structure composed of two n-doped AlAsSb/GaSb distributed Bragg reflectors, a type-I GaInAsSb/AlGaAsSb multi-quantum-well active region and tunnel junction. Quasi continuous-wave operation demonstrated at 2.3 µm up to room temperature. Threshold current densities 0.8 0.6 kA/cm2 are obtained 300 280 K for 80 µm-diameter devices (1 µs pulses, 10% duty cycle). A peak output optical power...

Plant height is commonly used to characterize crops in various domains such as plant breeding or precision farming. Despite significant advances sensing technologies, still very often measured manually many research applications where high-throughput alternatives are not always suitable. Here, we have developed a low cost, open-source ultrasonic device for semi-automated measurements small- medium-scale applications. The main innovation compared previous developments the combination of...

In this paper, the process of fabrication GaSb-based electrically injected resonant-cavity LEDs near 2.3 mum is detailed. The electrical and optical properties these diodes operating in continuous wave at room temperature are also presented. different tested monolithic structures have similar designs with two doped AlAsSb/GaSb Bragg mirrors an active region eight GaInAsSb quantum wells. Performances devices containing or not n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

The main aim of this study was to use Empirical mapping test the efficiency local low cost wireless network sensors (LPWAN - Low-Power Wide Area Network) before being applied in real wine-growing conditions. second obtain information on communication distances be expected from a LPWAN, taking into account specific needs and conditions vineyard. A hand-held autonomous end-device specifically built simulate short messages sent by via locally designed LPWAN. This device used quality different...

Detailed and precise knowledge of production parameters (yield, quality, health status, etc.) in agriculture is the basis for analyzing effect any agricultural practice. Fine mapping makes it possible to identify origin observed variability, whether associated with environmental factors or practices. In viticulture, real commercial context, these data are rare because monitoring systems embedded on harvesting machines grape yield quality not yet available. As a result, they costly and/or...

The first electrically-pumped GaSb-based vertical cavity surface emitting lasers above 2.5 µm at room temperature are reported. This monolithic all-epitaxial structure is composed of two n-doped AlAsSb/GaSb DBRs, a type-I GaInAsSb/AlGaAsSb multi-quantum-well active region and an InAsSb/GaSb tunnel junction. Devices with diameter 30 operate in quasi-CW (1 µs, 5%) 2.52 300 K. A minimum threshold current 4.7 kA/cm2 pulsed operation (100 ns, 0.5%) was obtained 251 K these devices.

The approach adopted in the present work was to increase pressure within an integrating sphere system number density of molecules gas cell and hence obtain a significant absorption order improve sensitivity measurement system. This feasibility study has allowed assessment net gain with rise highlights validity domain linear operating regime relative Beer's law. Experiments were conducted on oxygen A-band. peaks at 760 nm typically measured 50 mm diameter under various pressures. Tests...

&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Aims:&lt;/strong&gt; This work aims to study the quality of low cost Digital Surface Models (DSMs) obtained with Unmanned Aerial Vehicle (UAV) images and test whether these DSMs meet common requirements wine industry.&lt;/p&gt;&lt;p justify;"&gt;&lt;strong&gt;Methods results: &lt;/strong&gt;Experiments were carried out on a 4-ha vineyard located 10 km north Beziers (France). The experimental site presents slope aspect variations...

In this article, a set of 50 turbid liquid samples with different levels absorption and scattering properties were prepared measured at various orientations polarizers analyzers to obtain the 16 elements complete Muller matrix. Partial Least Square (PLS) was used build calibration models in order assess potential polarization spectroscopy through matrix predict chemical physical parameters.

Sugar beet is the second biggest world contributor to sugar production and only one grown in Europe. One of main limitations for its competitiveness lack effective tools assessing content unprocessed roots, especially breeding programs. In this context, a dedicated near infrared (NIR) fiber-optic probe based approach proposed. NIR technology widely used estimation vegetable products, while optic fibers allow wide choice technical properties configurations. The objective research was study...

The separation of the combined effects absorption and scattering in complex media is a major issue for better characterization prediction properties. In this study, an approach coupling polarized light spectroscopy Mueller matrix concept were evaluated to address issue. A set 50 turbid liquid optical phantoms with different levels properties made measured at various orientations polarizers analyzers obtain 16 elements complete VIS-NIR region. Partial least square (PLS) was performed build...