An optical fibre sensor for simultaneous temperature and humidity measurements consisting of one fibre Bragg grating (FBG) to measure temperature and a mesoporous film of bilayers of Poly(allylamine hydrochloride)(PAH) and silica (SiO2) nanoparticles deposited onto the tip of the same fibre to measure humidity is reported. The hygroscopic film was created using the layer-by-layer (LbL) method a...

Distributed optical fibre sensing, employing either Rayleigh, Raman, or Brillouin scattering, is the only physical-contact sensor technology capable of accurately estimating physical fields with spatial continuity along the fibre. This unique feature and the other features of standard optical fibre sensors (e.g., minimal invasiveness and lightweight, remote powering/interrogating capabilities) ...

By controlling the fibre geometry, the fraction of optical field within the holes and the inserted material of a photonic crystal fibre, we demonstrate that it is possible to engineer any arbitrary wavelength-dependent thermo-optic coefficient. The possibility of making a fibre with a zero temperature dependent thermo-optic coefficient, ideal for packaging of structured fibre gratings, is propo...

Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and...

We have reported the thermoluminescence (TL) response of five different diameters ~120, 241, 362, 483, and 604 μm of 6 mol percent Ge-doped optical fibres. The perfomance of the Ge-doped optical fibre are compared with commercially available TLD-100 chips (LiF:Mg,Ti) in terms of their sensitivity and minimum detectable dose (MDD). The irradiation was performed using X-ray machine (Model ISO ‘Na...

In this paper we have discussed a simulated long haul optical transmission system Over the single mode fibre which is prove to the liner chromatic dispersion as well as Non linearity. Both Parameter have been of great concern as these confine the overall Efficiency of the system. Loop control is commonly chosen as an important component in optical communication system. Loop control is very simp...

Introduction: All-optical wavelength converters (AOWC) are envisioned to be part of future high-speed networks. In particular, they might replace optical-to-electrical-to-optical (OEO) wavelength translator units in optical crossconnects [1]. However, to be practical, AOWCs must be able to convert signals that have been degraded during transmission over reasonable distances. Tolerance to timing...

We describe a novel approach for CMOS-compatible passively temperature insensitive silicon based optical devices using titanium oxide cladding which has a negative thermo-optic (TO) effect. We engineer the mode confinement in Si and TiO2 such that positive TO of Si is exactly cancelled out by negative TO of TiO2. We demonstrate robust operation of the resulting device over 35 degrees.

We study numerically depressed-index cladding, buried, micro-structured optical waveguides that can be formed in a lithium niobate crystal by femtosecond laser writing. We demonstrate to which extent the waveguiding properties can be controlled by the waveguide geometry at the relatively moderate induced refractive index contrasts that are typical of the direct femtosecond inscription.

Strong waveguide Bragg-gratings (10 dB reflectivity) were fabricated by the directwrite technique in ZBLAN glass. Based on a depressed cladding, an array of 169 periodic and in phase modifications was placed inside the core. OCIS codes: (230.7370) Optical devices: Waveguides; (230.1480) Bragg reflectors; (350.3390) Laser materials processing