Temperature Cross-Sensitivity for Highly Refractive Index Sensitive Nanocoated Long-Period Gratings

Pressure Sensing in High-Refractive-Index Liquids Using Long-Period Gratings Nanocoated with Silicon Nitride

The paper presents a novel pressure sensor based on a silicon nitride (SiNx) nanocoated long-period grating (LPG). The high-temperature, radio-frequency plasma-enhanced chemical-vapor-deposited (RF PECVD) SiNx nanocoating was applied to tune the sensitivity of the LPG to the external refractive index. The technique allows for deposition of good quality, hard and wear-resistant nanofilms as requ...

Highly Sensitive Refractive Index Sensor Based on Adiabatically Tapered Microfiber Long Period Gratings

We demonstrate a refractive index sensor based on a long period grating (LPG) inscribed in a special photosensitive microfiber with double-clad profile. The fiber is tapered gradually enough to ensure the adiabaticity of the fiber taper. In other words, the resulting insertion loss is sufficiently small. The boron and germanium co-doped inner cladding makes it suitable for inscribing gratings i...

Refractive index sensitivity of fibre optic long period gratings with SiO2 nanoparticle based mesoporous coatings

A fibre optic long period grating (LPG) with a nano-assembled mesoporous coating of alternate layers of poly (allylamine hydrochloride) (PAH) and SiO2 nanospheres was used for the development of a fibre-optic refractometer. PAH/SiO2 films of different thickness have been deposited onto LPG in order to study the effect of the film thickness on sensor performance. The device showed a sensitivity ...

Refractive Index Sensitivity in Thinned Uv and Arc Induced Long-period Gratings: a Comparative Study

In this work, a comparative study aimed to investigate the effects of cladding stripping on the external refractive index sensitivity in tapered and UV long period gratings is presented. Here, wet chemical etching combined with microscopic analysis allow us to identify the experimental dependence of the surrounding refractive index (SRI) sensitivity on the cladding radius for both grating types...

Improved Refractive Index Sensitivity Utilizing Long-Period Gratings with Periodic Corrugations on Cladding