A numerical model of the sensitivity of long period gratings fabricated by electric-arc in photonic crystal fibres to strain,
temperature and refractive index is proposed and evaluated by comparison to the experimental results. It is shown to be
superior to the commonly used semi-analytical method. The generalized modelling procedure is thoroughly explained in
order to facilitate its application to a wide range of long period gratings in different types of fibres.
This paper describes experimental and numerical results of the
plasma-assisted microfabrication of subwavelength structures by
means of point-by point femtosecond laser inscription. It is shown
that the spatio-temporal evolution of light and plasma patterns
critically depend on input power. Subwavelength inscription
corresponds to the supercritical propagation regimes when pulse
power is several times self-focusing threshold. Experimental and
numerical profiles show quantitative agreement.
We present an adaptive mesh approach to high performance comprehensive investigation of dynamics of light and plasma pattens during the process of direct laser inscription. The results reveal extreme variations of spatial and temporal scales and tremendous complexity of these patterns which was not feasible to study previously.
Long period gratings in two types of photonic crystal fibre have been studied. The gratings display negligible temperature sensitivity but useful sensitivity to other measurands. Theoretical modelling suggests that unusual phase matching conditions apply.