CO2-laser Writing of Long-period Gratings in Optical Fibres and Waveguides

Long-period fibre grating (LPFG) has emerged as a versatile wavelength-selective fibre-optic component for application in optical communications, signal processing, and sensing. Among the many methods for the fabrication of LPFGs, the CO2-laser writing method is particularly flexible, as it can apply to practically any optical fibres and the writing process can be computer-controlled to produce complicated grating profiles. There is, however, much to study about this method on the understanding of the physical mechanisms involved and the optimization of the writing conditions for different kinds of fibres. The objectives of the project are:to write better LPFGs in different kinds of fibres through an investigation of the writing mechanisms; andto apply the method for the first time to the writing of long-period waveguide gratings (LPWGs), namely, gratings formed in planar waveguides.The project will lead to improved LPFGs and a new method of fabricating LPWGs.