Research of FBG multiplexing/demodulation on LPG

摘要

Long-period grating(LPG) which has a grating period of more than lOOum is a new kind of fiber grafting and its principle is that optical power is coupled from the forward transmission fundamental core mode to the forward transmission cladding modes and is attenuated after some distance. Transmission spectrum of LPG has a range close to linearity in both side of the peak. This range can be use as double edge filter on this property. Cascaded LPGs have special spectrum which is used as filters in multiple technology .