Long period grating was UV inscribed into a multicore fiber consisting of 120 single mode cores. The that hosts the fusion spliced at both ends. splice creates taper transition between two types produces nonadiabatic evolution; this results in illumination all modes fiber. spectral characteristics device as function curvature were investigated. yielded significant sensitivity high 1.23 nm/m(-1) and 3.57 dB/m(-1) to ultra-low values from 0 1 m(-1). This can also distinguish orientation...

A low cost interrogation scheme is demonstrated for a refractometer based on an in-line fiber long period grating (LPG) Mach–Zehnder interferometer. Using this the minimum detectable change in refractive index of Δn∼1.8×10−6 obtained, which highest resolution achieved using LPG device, and comparable to precision techniques used industry including high performance liquid chromatography ultraviolet spectroscopy.

We investigate the modification of optical properties carbon nanotubes (CNTs) resulting from a chemical reaction triggered by presence specific compound (gaseous dioxide (CO2)) and show this mechanism has important consequences for sensing. CNTs have attracted significant research interest because they can be functionalized particular chemical, yielding physical response which suggests many potential applications in fields nanotechnology So far, however, utilizing their purpose proven to...

We report an investigation of thermal properties long-period fiber gratings (LPFGs) various periods fabricated in the conventional B-Ge codoped fiber. It has been found that temperature sensitivity LPFGs produced can be significantly enhanced as compared with standard telecom A total 27.5-nm spectral shift was achieved from only 10/spl deg/C change for LPFG 240-μm period, demonstrating a first ever reported high 2.75 nm//spl deg/C. Such may lead to high-efficiency and low-cost...

We present a plasmonic biosensor capable of detecting the presence bisphenol A in ultra-low concentrations, yielding wavelength shift 0.15 ± 0.01 nm response to solution 1 fM concentration with limit detection 330 70 aM The biosensing device consists an array gold nano-antennae total length 2.3 cm that generate coupled localised surface plasmons (cLSPs) and is covalently modified aptamer specific for recognition. fabricated on lapped section standard telecommunication optical fibre, allowing...

Long period gratings (LPGs) were written into a D-shaped single-mode fiber. These LPGs subjected to range of curvatures, and it was found that as curvature increased, there increasingly strong coupling certain higher order cladding modes without the usual splitting stopbands. A bend-induced stopband yielded spectral sensitivity 12.55 nm/spl middot/m for 2.2/spl times/10/sup -2/ deg/C/sup -1/ temperature. It also wavelength separation between adjacent stopbands varied linearly function...

We present a novel device for the characterisation of static magnetic fields through monitoring wavelength shifts femtosecond inscribed fibre Bragg grating and micromachined slot, coated with Terfenol-D. The was sensitive to can be used as vectoral sensor detection low 0.046 mT resolution ± 0.3mT in transmission 0.7mT reflection. use laser both inscribe FBGs micromachine slot single stage prior coating significantly simplifies fabrication.

The fabrication and characterization of long-period gratings (LPGs) in fiber tapers is presented alongside supporting theory. devices possess a high sensitivity to the index aqueous solutions due an observed spectral bifurcation effect, yielding limiting resolution /spl plusmn/8.5/spl times/10/sup -5/ for with range 1.330-1.335.

We demonstrate the use of tilted fiber gratings to assist generation localized infrared surface plasmons with short propagation lengths and a sensitivity dλ/dn = 3365 nm in aqueous index regime. It was also found that resonances could be spectrally tuned over 1000 at same spatial region high coupling efficiency (in excess 25 dB) by altering polarization light illuminating device.

In non-invasive ventilation, continuous monitoring of respiratory volumes is essential. Here, we present a method for the measurement by single fiber-grating sensor bending and provide proof-of-principle applying calibration-test procedure on set 18 healthy volunteers. Results establish linear correlation between change in lung volume corresponding local thorax curvature. They also show good accuracy measurements tidal minute different types breathing. The proposed technique does not rely...

A compact scheme for simultaneous temperature and surrounding refractive index (SRI) measurement using two long-period gratings (LPGs) of different periods inscribed side-by-side in a single piece double-cladding fibre is presented. One the LPGs sensitive to both SRI temperature, whilst second only.

We demonstrate the use of tilted fiber gratings to assist with generation infrared surface plasmons on a metal film coating flat D-shaped fiber. The wavelength strong (>25 dB) resonance is tunable over ~1000 nm by adjusting polarization state light and highly sensitive refractive index any aqueous medium surrounding (sensitivity=3365 nm).

A series of in-line curvature sensors on a garment are used to monitor the thoracic and abdominal movements human during respiration. These results obtain volumetric tidal changes torso in agreement with spirometer simultaneously at mouth. The based long-period gratings (LPGs) written progressive three-layered fiber render LPGs insensitive refractive index external fiber. sensor consists grating laid carbon ribbon, which is then encapsulated low-temperature curing silicone rubber. have...

An array of in-line curvature sensors on a garment is used to monitor the thoracic and abdominal movements human during respiration. The results are obtain volumetric changes torso in agreement with spirometer simultaneously at mouth. 40 fiber Bragg gratings produce 20 different locations, each sensor consisting two gratings. adjoining encapsulated into low-temperature-cured synthetic silicone. wavelength interrogated by commercially available system from Moog Insensys, calibrated recover...

A long period grating (LPG) written in a standard optical fibre was modified by using femtosecond laser to induce an asymmetric change the cladding's refractive index. This device produced blue and red wavelength shifts depending on orientation of applied curvature, with maximum sensitivities −1.6 nm m +3.8 m, suggesting that this type LPG may be useful as shape sensor.

A femtosecond laser has been used to asymmetrically modify the cladding of fiber containing long-period gratings. Following modification, devices in single-mode are shown be capable sensing magnitude and direction bending one plane by producing blue red wavelength shifts depending upon orientation bend. The resulting curvature sensitivities were -1.62 +3.82 nmmiddotm. Devices have also produced using an elliptical core study effects modification on two polarization eigenstates. applied fast...

We demonstrate surface plasmon resonance (SPR) fiber devices based upon ultraviolet inscription of a grating-type structure into both single-layered and multilayered thin films deposited on the flat side lapped D-shaped fiber. The were fabricated from germanium, while ones comprised layers silica, silver. Some operated in air with high coupling efficiency excess 40 dB an estimated index sensitivity Δλ/Δn=90 nm 1 to 1.15 range, others provided Δλ/Δn=6790 for refractive indices 1.33 1.37.

A series of waveguides was inscribed in a borosilicate glass (BK7) by an 11 MHz repetition rate femtosecond laser operating with pulse energies from 16 to 30 nJ and focused at various depths within the bulk material. The index modification measured using quantitative phase microscopy technique that revealed central changes ranging 5×10−3 10−2, leading exhibited propagation losses 0.2 dB/cm wavelength 633 nm 0.6 1550 efficient mode matching, less than dB, standard optical fibers. Analysis...