25 research outputs found
Curvature sensing using a hybrid polycarbonate-silica multicore fiber
We report on the development of a novel hybrid glass-polymer multicore fiber integrating three 80 µm polyimide-coated silica fibers inside a 750 µm polycarbonate cladding. By inscribing an array of distributed FBGs along each segment of silica fiber prior to the hybrid fiber drawing, we demonstrate a curvature sensor with an unprecedented precision of 296 pm/m−1 around 1550 nm, about 7 times more sensitive than sensors based on standard 125 µm multicore fibers. As predicted by theory, we show experimentally that the measured curvature is insensitive to temperature and strain. Also, a more precise equation to describe the curvature on a simple bending setup is presented. This new hybrid multicore fiber technology has the potential to be extended over several kilometers and can find high-end applications in 3D shape sensing and structural health monitoring
Flexible trans-jacket inscription of fiber Bragg gratings for directional distributed sensing
An array of 18 FBGs spectrally distributed over 70 nm was written in a polyimide-coated fiber, with a single uniform phase-mask, by applying
strain on the fiber prior to exposition. This flexible method will be used to develop directional sensor for distributed sensing based on a hybrid glasspolymer multicore fiber
Tunable distributed sensing performance in Ca-based nanoparticle-doped optical fibers
Rayleigh scattering enhanced nanoparticle-doped optical fibers is a technology very promising for distributed sensing applications, however, it remains largely unexplored. This work demonstrates for the first time the possibility of tuning Rayleigh scattering and optical losses in Ca-based nanoparticle-doped silica optical fibers by controlling the kinetics of the re-nucleation process that nanoparticles undergo during fiber drawing by controlling preform feed, drawing speed and temperature. A 3D study by SEM, FIB-SEM and optical backscatter reflectometry (OBR) reveals an early-time kinetics at 1870 °C, with tunable Rayleigh scattering enhancement 43.2–47.4 dB, regarding a long-haul single mode fiber, SMF-28, and associated sensing lengths of 3–5.5 m. At 2065 °C, kinetics is slower and nanoparticle dissolution is favored. Consequently, enhanced scattering values of 24.9–26.9 dB/m and sensing lengths of 135–250 m are attained. Finally, thermal stability above 500 °C and tunable distributed temperature sensitivity are proved, from 18.6 pm/°C to 23.9 pm/°C, ∼1.9–2.4 times larger than in a SMF-28. These results show the promising future of Rayleigh scattering enhanced nanoparticle-doped optical fibers for distributed sensing
The EcoChip : a wireless multi-sensor platform for comprehensive environmental monitoring
This paper presents the EcoChip, a new system
based on state-of-the-art electro-chemical impedance (EIS)
technologies allowing the growth of single strain organisms
isolated from northern habitats. This portable system is a complete
and autonomous wireless platform designed to monitor and
cultivate microorganisms directly sampled from their natural
environment, particularly from harsh northern environments.
Using 96-well plates, the EcoChip can be used in the field for realtime monitoring of bacterial growth. Manufactured with highquality electronic components, this new EIS monitoring system is
designed to function at a low excitation voltage signal to avoid
damaging the cultured cells. The high-precision calibration
network leads to high-precision results, even in the most limiting
contexts. Luminosity, humidity and temperature can also be
monitored with the addition of appropriate sensors. Access to
robust data storage systems and power supplies is an obvious
limitation for northern research. That is why the EcoChip is
equipped with a flash memory that can store data over long
periods of time. To resolve the power issue, a low-power microcontroller and a power management unit control and supply all
electronic building blocks. Data stored in the EcoChip’s flash
memory can be transmitted through a transceiver whenever a
receiver is located within the functional transmission range. In this
paper, we present the measured performance of the system, along
with results from laboratory tests in-vitro and from two field tests.
The EcoChip has been utilized to collect bio-environemental data
in the field from the northern soils and ecosystems of
Kuujjuarapik and Puvirnituq, during two expeditions, in 2017 and
2018, respectively. We show that the EcoChip can effectively carry
out EIS analyses over an excitation frequency ranging from 750
Hz to 10 kHz with an accuracy of 2.35%. The overall power
consumption of the system was 140.4 mW in normal operating
mode and 81 µW in sleep mode. The proper development of the
isolated bacteria was confirmed through DNA sequencing,
indicating that bacteria thrive in the EcoChip’s culture wells while
the growing conditions are successfully gathered and stored
Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications
Space-division multiplexing (SDM), whereby multiple spatial
channels in multimode1 and multicore2 optical fibres are used
to increase the total transmission capacity per fibre, is being
investigated to avert a data capacity crunch3,4 and reduce the
cost per transmitted bit. With the number of channels employed
in SDM transmission experiments continuing to rise, there is a
requirement for integrated SDM components that are scalable.
Here, we demonstrate a cladding-pumped SDM erbium-doped
fibre amplifier (EDFA) that consists of six uncoupled multimode
erbium-doped cores. Each core supports three spatial modes,
which enables the EDFA to amplify a total of 18 spatial channels
(six cores × three modes) simultaneously with a single pump
diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and <7 dB noise
figure over the C-band. This cladding-pumped EDFA enables
combined space-division and wavelength-division multiplexed
transmission over multiple multimode fibre spans
The Maunakea Spectroscopic Explorer Book 2018
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is
intended as a concise reference guide to all aspects of the scientific and
technical design of MSE, for the international astronomy and engineering
communities, and related agencies. The current version is a status report of
MSE's science goals and their practical implementation, following the System
Conceptual Design Review, held in January 2018. MSE is a planned 10-m class,
wide-field, optical and near-infrared facility, designed to enable
transformative science, while filling a critical missing gap in the emerging
international network of large-scale astronomical facilities. MSE is completely
dedicated to multi-object spectroscopy of samples of between thousands and
millions of astrophysical objects. It will lead the world in this arena, due to
its unique design capabilities: it will boast a large (11.25 m) aperture and
wide (1.52 sq. degree) field of view; it will have the capabilities to observe
at a wide range of spectral resolutions, from R2500 to R40,000, with massive
multiplexing (4332 spectra per exposure, with all spectral resolutions
available at all times), and an on-target observing efficiency of more than
80%. MSE will unveil the composition and dynamics of the faint Universe and is
designed to excel at precision studies of faint astrophysical phenomena. It
will also provide critical follow-up for multi-wavelength imaging surveys, such
as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field
Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation
Very Large Array.Comment: 5 chapters, 160 pages, 107 figure
Ultrafast cleaning of methylene blue contaminated water accelarating photocatalytic reaction rate of the BiVO4 nanoflakes under highly intense sunlight irradiation
The sustainable rapid wastewater treatment process is the greatest challenge in the 21st century as the demand of fresh and clean water is increasing with growing population worldwide. Herein, an emergent technique to clean dye contaminated wastewater using sunlight is reported. The highly efficient sunlight driven photocatalyst BiVO4 nanoflakes with optical band gap of 2.63 eV have been prepared by cost-effective hydrothermal method and the photocatalytic methylene blue (MB) degradation activity of BiVO4 nanoflakes has been enhanced accelarating the photocatalytic reaction rate. The BiVO4 nanoflakes can degrade 88.86 % of methylene blue within 60 minutes for 300 mW/cm2 sunlight irradiation, whereas only 32.30 % degradation occurs for ordinary sunlight (74 mW/cm2) irradiation. The MB degradation occurs faster due to increase of photocatalytic reaction rate to 0.033 min−1 from 0.006 min−1 for tuning sunlight irradiation intensity to 300 mW/cm2 from 74 mW/cm2. This technique will open new technological opportunity for ultrafast cleaning of dye contaminated wastewater using sunlight