Flexible manufacturing method for long-period fibre gratings with arbitrary index modulation profiles

摘要

Special long-period fibre gratings (LPGs) are needed in multiple applications. For example, LPGs are employed as mode converters in the forward direction to utilise the waveguide dispersion of higher order modes. Other applications are gain flattening of optical amplifiers or filtering in general. In this paper, we propose a flexible manufacturing method for LPGs, which enables the generation of tailored arbitrary index modulation profiles. The results of apodized and chirped gratings are presented, which show the flexibility and reliability of the writing set-up.