An analysis of optical properties of fundamental-mode in waveguide tapered fibers is theoretically investigated and realized in this paper. The waveguide device is tapering an SMF-28 fiber to few tens of micrometers of diameter. For discussing the cladding size of waveguide structure affects the fundamental-mode cutoff (FMC) and the optical characteristics of the devices, to etch outer cladding...

A novel geometry for enhancing the sensitivity of intensity modulated refractometric fiber optic sensor for detection of adulteration level in diesel by kerosene is proposed. In this multimode plastic optical fiber is uncladded for specific length and bent into S shape. This geometry is simulated and analyzed using Beam Propagation Method in Beam prop RSOFT software. When sensor is immersed in ...

Surface plasmon polaritons (SPP) can be excited on metal-coated optical fibres, enabling the accurate monitoring of refractive index changes. Configurations reported so far mainly operate in liquids but not in air because of a mismatch between permittivities of guided light modes and the surrounding medium. Here we demonstrate a plasmonic optical fibre platform that overcomes this limitation. T...

A range of distributed fibre optic sensors for the detection and location of aqueous, chemical and hydrocarbon fluid spills is presented. The sensors incorporate polymers that convert the swelling into a localised loss on an optical fibre when fluid exposure occurs. Optical Time Domain Reflectometry (OTDR) techniques are employed to rapidly detect and locate target liquids and chemicals at mult...

Using the Condon model to describe the dispersive behavior of optically active media, we analyze two different classes of waves in chiral optical fibers: surface and semileaky modes. Only when the cladding is chiral, semileaky modes do exist; accordingly, optical fibers with either chiral or achiral cores, but always with a chiral cladding, are considered. Two fundamental modes, corresponding t...

The regeneration of UV-written long period gratings (LPG) in boron-codoped germanosilicate "W" fibre is demonstrated and studied. They survive temperatures over 1000 °C. Compared with regenerated FBGs fabricated in the same type of fibre, the evolution curves of LPGs during regeneration and post-annealing reveal even more detail of glass relaxation. Piece-wise temperature dependence is observed...

We propose a cladding engineering method that flexibly modifies the radiation patterns and rates of metal-clad nanoscale optical cavity. Optimally adjusting the cladding symmetry of the metal-clad nanoscale optical cavity modifies the modal symmetry and produces highly directional radiation that leads to 90% coupling efficiency into an integrated waveguide. In addition, the radiation rate of th...

For a fiber optical surface plasmon resonance (SPR) sensor a short part of its cladding should be removed to coat a thin layer of a metal. Usually this is problematic when an optical fiber with small core diameter is used. In this paper, a new method using µliter droplet of the HF acid for short fiber optical taper fabrication is reported. Using this method in a multi-mode optical fiber w...

This study presents a new mechanical tube cladding process named punch plastic deformation pipe cladding (PPDPC) based on local deformation by pressing a punch into the inner layer of the bimetal tube. To investigate the capability of the process, stainless steel tube (as the inner layer) is bonded to a carbon steel pipe (as the outer layer) to fabricate a bimetal pipe. Shear punch tests were u...

A metre-length flexible hollow glass fibre with 20 µm-bore and 1.5 mm-cladding diameters for transporting a synchrotron X-ray beam and controlling the trajectory has been examined. The large cladding diameter maintains a moderate curvature to satisfy the shallow glancing angle of total reflection. The observed transmission efficiency was more than 20% at 12.4 keV. As a demonstration, a wide-are...