Cladding-mode extraction from long-period fibre grating using self-aligned core-mode blocker

A novel method is presented of fabricating a core-mode blocker for use in long-period fibre gratings by forming a self-aligned absorber on the end of the fibre core. The absorber efficiently suppresses the core-mode power and allows the cladding-mode radiation to pass through, thereby resulting in a bandpass output at the resonant wavelengths