Loss-tunable long period fibre grating made from etched corrugation structure

A new long period fibre grating (LPFG) is demonstrated, for which the transmission loss at the resonance peak can be tuned from 1.2 to 29 dB after fabrication. For such a large tuning range, the shift of the peak loss wavelength is <2.2 nm. The tunability is obtained by adjusting the amount of stress applied to the LPFG, composed of an etched corrugation structure. No light exposure is required.