Nanoimprinted Polymer Micro/Nanofiber Bragg Gratings for High-Sensitivity Strain Sensing

By using a simple and low-cost nanoimprinting technique, polymer micro/nanofiber Bragg gratings (MNFBGs) are fabricated with a ~551-nm grating period and a grating depth >;10 dB around 1.5-μm wavelength. As-fabricated MNFBGs also show high compactness to optical fiber systems and large dynamic range. Using a 2.5-μm-wide and 1.4-μm-thick MNFBG, we demonstrate strain sensing with a high sensitivity of -2.5 pm/με.