48 research outputs found
OPENMODS 2.0 “Instrument Jamming Meeting” report
Major achievements
The feedback provided by potential users on their needs was very much appreciated. They
underlined the importance of having:
● an easy to deploy instrument (i.e.: from small fishing boats);
● multi-parameter sensors in ONE device;
● less maintenance effort
and prioritized the variables to measure.
Although, there are technical limitations and different solutions and there is no one tool that
can do everything, which is low cost, has high resolution and low maintenance, the
outcomes of the platforms/sensors/communications working group meet the main
requirements that emerged.
Priority was given to:
● a platform that will operate in drifter mode which is extremely easy to deploy and
perfect for studies associated with search and rescue operations (another need that
has emerged). It also constantly guarantees the knowledge of the instrument position.
The platform can be easily converted into the moored mode.
● temperature and pressure sensors. The sensors will be low -cost with the idea to
replace them rather than calibrate them;
● LoRaWAN communications preferably with Bluetooth integration for the in-situ
download of the data
Ellipsometric investigation of porous silicon layers for the design of a DBR
Porous silicon layers (PSL) were fabricated by electrochemical etching and
investigated by spectroscopic ellipsometry (SE) in the energy range 0.6−5
eV. Within the effective medium approximation (EMA) and through an optical
model consisting of a mixture of void and crystalline silicon (cSi), we were
able to determine the porosity (void concentration) and the thicknesses of
the PSL. The PSL were divided into several sublayers in order to obtain the
best agreement between measured and simulated spectra. Once the etching
parameters have been controlled and by choosing the appropriate conditions,
it was possible to design a distributed Bragg reflector (DBR) with a high
reflectivity band centered at 800 nm. This DBR consists on stacks of
alternate PSL having two different refractive indices