In this paper, we demonstrate the transmission spectral and surrounding refractive index (SRI) sensing performance of long-period fiber gratings (LPFGs) at 2 μm waveband. The cladding modes operat…
We demonstrate the fabrication of long-period fiber gratings (LPFGs) in an elliptical core few-mode fiber (e-FMF) by CO 2 laser. The mode conversion from fundamental mode to high-order modes (LP 11…