Tilted FBG

The same between the Tilted FBG (TFBG) and the standard FBG is that the core refractive index modulation is uniform, the difference is that the TFBG will have multiple mode couplings due to the tilt angle between the grating and the axial direction, mainly including the couplings between the fiber core guided modes, the coupling between the fiber core guided mode and the cladding mode, and the coupling between the fiber core guided mode and the radiating mode, the cladding is infinite. The coupling efficiency between modes and the bandwidth of the leaked light are determined by the tilt angle of the Tilted FBG and the depth of refractive index modulation.