Biochemical sensor based on a novel all-fibre cavity ring down spectroscopy technique incorporating a tilted fibre Bragg grating

A novel all-fibre cavity ring down spectroscopy technique is demonstrated where a tilted fibre Bragg grating in the cavity provides sensitivity to surrounding refractive index. A decay time of 450ns was attained when sensing water.

Low cost distributive sensing smart surface

We describe a low cost approach to interrogating a distributive tactile surface instrumented with fibre Bragg grating sensors. The system can determine the position, shape, and orientation of an object on the surface.

The application of a long period grating sensor array scheme to human respiratory plethysmography

Preliminary results are given for a long period grating sensing array scheme based upon a derivative spectroscopy interrogation technique for Human Respiratory Plethysmography with simultaneous measurements of a spirometer, reasonable agreement with recorded volumetric changes was found.

Surface plasmon resonance generation utilising gratings for biochemical sensing

We demonstrate the use of gratings to assist in the generation of surface plasmon resonances resulting in a device having a high index resolution of 3×10-5 in the aqueous index regime.

Highly birefringent long period gratings fabricated with femtosecond laser

Long Period Gratings (LPG) in standard fibre have been manufactured with a sharply focused near infrared (NIR) femtosecond laser beam. Polarization splitting of the attenuation bands is strongly dependent upon the inscription power.

Femtosecond laser inscribed phase masks for fibre Bragg grating sensor inscription

We present femtosecond laser inscribed phase masks for the inscription of Bragg gratings in optical fibres. The principal advantage is the flexibility afforded by the femtosecond laser inscription, where sub-surface structures define the phase mask period and mask properties. The masks are used to produce fibre Bragg gratings having different orders according to the phase mask period. The work demonstrates the incredible flexibility of femtosecond lasers for the rapid prototyping of complex and reproducible mask structures. We also consider three-beam interference effects, a consequence of the zeroth-order component present in addition to higher-order diffraction components. © 2012 SPIE.

112Gbit/s RF assisted dual-carrier DP-16-QAM in installed and new build WDM applications

The performance of a 112Gbit/s dual-carrier DP-16-QAM channel in various WDM configurations is characterized. Variations of the dispersion map, ROADM count and system length are experimentally evaluated and compared with numerical simulation. © 2012 OSA.

Transverse loading of multicore fibre gratings

We report experimental measurements of the reflection spectra of Bragg gratings inscribed in 4-core fibres under transverse loading. Broadening and splitting of the Bragg peaks from each core are observed as a function of load and fibre orientation.

Tunable dispersion slope compensator using novel tailored Gires-Tournois etalons

We present a novel concept of tailored GTE structure and show that such devices are very useful for the realization of DSC with almost arbitrary dispersion profile and also with tunability in dispersion slope.

5,745 km DWDM transcontinental field trial using 10 Gbit/s dispersion managed solitons and dynamic gain equalization

Error free unregenerated transmission is demonstrated looped-back over 5,745 km (62 spans) of installed SSMF along the Adelaide-Perth leg of the IP1 Australia network, which is now the world's longest commercially deployed unregenerated 10 Gbit/s DWDM terrestrial transmission system. © 2000 Optical Society of America.

High sensitivity sensors utilising characteristics of dispersion-turning-point of long-period gratings in B/Ge co-doped fibre

Systematically investigated the waveguide dispersion characteristics of LPFGs. It has been revealed that the coupled cladding modes resonating in the dispersion-turning-point region are intrinsically sensitive to the external perturbation. Thus, LPFG-based application devices requiring good stability should avoid this region. On the other hand, this mode ultra-sensitive-zone can be explored to realise sensors and tuneable filters of high efficiency.

A high sensitivity long period grating Mach-Zehnder refractometer

A refractive index sensing system has been demonstrated, which is based upon an in-line fibre long period grating Mach-Zehnder interferometer with a heterodyne interrogation technique. This sensing system has comparable accuracy to laboratory-based techniques used in industry such as high performance liquid chromatography and UV spectroscopy. The advantage of this system is that measurements can be made in-situ for applications in continuous process control. Compared to other refractive index sensing schemes using LPGs, this approach has two main advantages. Firstly, the system relies on a simple optical interrogation system and therefore has the real potential for being low cost, and secondly, so far as we are aware it provides the highest refractive index resolution reported for any fibre LPG device.

Sensing applications of arrayed waveguide grating devices

Progress in optical fibre sensor research has often been achieved by taking advantage of components developed for use in telecommunications, where the greater existing market is able to support the rapid commercialisation of novel devices. In the last few years there has been considerable interest in the telecommunications community in deploying arrayed waveguide gratings (AWGs) produced in a range of technologies in a variety of roles. We feel it is therefore surprising that there have been very few reports of research into using AWGs for sensing. In this paper we consider some possible roles for these devices in interrogation systems for interferometric and fibre Bragg grating (FBG) sensors.

Polarization effects in polymer FBGs:study and use for transverse force sensing

Bragg gratings photo-inscribed in polymer optical fibers (POFs) are more sensitive to temperature and pressure than their silica counterparts, because of their larger thermo-optic coefficient and smaller Young's modulus. Polymer optical fiber Bragg gratings (POFBGs) are most often photo-written in poly(methylmethacrylate) (PMMA) based materials using a continuous-wave 325 nm HeCd laser. In this work, we present the first study about birefringence effects in POFBGs manufactured in different types of fiber. To achieve this, highly reflective (> 90%) gratings were produced with the phase mask technique. Their spectral response was then monitored in transmission with polarized light. Polarization dependent loss (PDL) and differential group delay (DGD) were computed from the Jones matrix eigenanalysis using an optical vector analyzer. Maximum values exceeding several dB and a few picoseconds were obtained for the PDL and DGD, respectively. An inverse scattering technique applied to the experimental data provided an estimate of the photo-induced birefringence value arising from the side fabrication process. The response to lateral force was finally investigated for various incident directions using the PDL response of FBGs manufactured in step-index POFs. As the force induced birefringence adds to the photo-induced one, a force dependent evolution of the PDL maximum value was noticed, with a good temperature-insensitivity.

Highly birefringent long period gratings fabricated with femtosecond laser

Long Period Gratings (LPG) in standard fiber have been manufactured with a sharply focused near infrared (NIR) femtosecond laser beam. Polarization splitting of the attenuation bands is strongly dependent upon the inscription power.