1,721,165 research outputs found
Fabrication and Characterization of Long-Period Gratings in Hollow Core Fibers by Electric Arc Discharge
No full textIn this paper we report on the fabrication and characterization of Long Period Gratings (LPGs) in hollow-core air-silica photonic bandgap fibers (HC-PCFs). The fabrication procedure is based on a pressure assisted Electrode Arc Discharge (EAD) technique. It relies on the combined use of EAD step, to locally heat the HC fiber, and of a static pressure (slightly higher than the external one) inside the fiber holes, to modify the holes. Here, the experimental fabrication of LPG prototypes with different periods and lengths are discussed. And, the sensitivity of LPGs in HC-PCF to environmental parameters such as strain, temperature and static pressure are presented and discussed
Design and analysis of an integrated antiresonant reflecting optical waveguide refractive-index sensor
No full textSensing features of long period gratings in hollow core fibers
No full textWe report the investigation of the sensing features of the Long-Period fiber Gratings (LPGs) fabricated in hollow core photonic crystal fibers (HC-PCFs) by pressure assisted Electric Arc Discharge (EAD) technique. In particular, the characterization of the LPG in terms of shift in resonant wavelengths and changes in attenuation band depth to the environmental parameters: strain, temperature, curvature, refractive index and pressure is presented. The achieved results show that LPGs in HC-PCFs represent a novel high performance sensing platform for measurement of different physical parameters including strain, temperature and, especially, for measurements of environmental pressure. The pressure sensitivity enhancement is about four times greater if we compare LPGs in HC and standard fibers. Moreover, differently from LPGs in standard fibers, these LPGs realized in innovative fibers, i.e. the HC-PCFs, are not sensitive to surrounding refractive inde
Deformation Monitoring of a Tracking Particle Detector using Fiber Bragg Grating sensors
No full textARROW structures for sensing applications
No full textIn this paper two sensing applications of Antiresonant Reflecting Optical Waveguide (ARROW) structures are proposed. In the first, we show that, by a suitable design, a conventional ARROW waveguide can be turned in an integrated optical refractometer useful in chemical and biochemical sensing. In the second application, using some peculiar properties of ARROW structures, we have designed and realized an integrated flow cell by an hollow core ARROW waveguide
Single and multiple phase shifts tilted fiber Bragg gratings
Full text linkThe spectral behavior of single and multiple phase shifts tilted fiber Bragg gratings has been experimentally investigated. To this aim, a simple and cost-effective postprocessing technique based on local thermal treatment was used to create arbitrary phase shifts along the tilted grating structure. In particular, UV written tilted fiber Bragg gratings were treated by the electric arc discharge to erase the refractive index modulation in well-defined regions. We demonstrate that these defects give rise to interference pattern for all modes, and thus defect states can be achieved within all the attenuation bands, enabling a simple wavelength independent spectral tailoring of this class of device
Silicon micromachined hollow optical waveguides for sensing applications
No full textNovel micromachined optical waveguides useful for sensing applications are proposed. The waveguide is designed as hollow-core antiresonant reflecting optical waveguide (ARROW) and can be easily fabricated using standard silicon micromachining techniques. The hollow structure permits to use the core to confine simultaneously the light and the substance to be probed, leading to an increase of the interaction efficiency. Numerical simulations, performed using finite element method technique, show that with a suitable design these waveguides can be used in sensing applications, where the substances under test can be gases or liquids
Self temperature referenced refractive index sensor by non-uniform thinned fiber Bragg gratings
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Nonuniform thinned fiber Bragg gratings for simultaneous refractive index and temperature measurements
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