[EN] We demonstrate 20 dB long period grating (LPG) fast inscription in microstructured polymer optical fibers (mPOFs) using a point-by-point technique obtaining an LPG total length of 25 mm. Two 248 nm UV laser pulses of 15 ns duration have been employed for every inscription point, which means a time reduction by over 21 times compared with the fastest inscription time already reported in literature. The device has been fabricated in a single-mode mPOF with a core that has been doped with benzyl dimethyl ketal for photosensitivity enhancement. Moreover, we characterize the strain and temperature responses and the stability of the fabricated gratings response under different conditions in order to assess the viability for different applications.

This work was supported in part by the Fundacao para a Ciencia e Tecnologia/MEC through national funds, in part by FEDER-PT2020 partnership agreement under the Projects UID/EEA/50008/2013, in part by the Research Excellence Award Programme GVA PROMETEO 2017/103 Future Microwave Photonic Technologies and Applications and Fundamental Research Funds for the Heilongjiang Provincial Universities under Grant KJCXZD201703. The work of C. Marques was supported by the FCT through the Fellowship under Grant SFRH/BPD/109458/2015.