Post-treatment techniques for enhancing mode-coupling in long period fiber gratings induced by CO₂ laser

Abstract

Two promising post-treatment techniques, i.e. applying tensile strain and rising temperature, are demonstrated to enhance the mode-coupling efficiency of the CO₂-laser-induced long period fiber gratings (LPFGs) with periodic grooves. Such two post-treatment techniques can be used to enhance the resonant attenuation of the grating to achieve a LPFG-based filter with an extremely large attenuation and to tailor the transmission spectrum of the CO₂-laser-induced LPFG after grating fabrication.

Keywords

Long period fiber gratings / fiber Bragg gratings / optical fiber sensor / temperature / tensile strain / optical fiber device

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