Dual-core mode converter with long period fiber grating

Mode division multiplexing is a new communication technology, which increases the communication capacity by increasing the multiplexing dimension of patterns. This paper introduces a new type of long period fiber grating mode converter based on hybrid dual-core fiber. The beam propagation method is used to numerically analyze the mode conversion from LP01 to LP21 and LP02 mode by changing the core distance. From the simulation results, LP01 converts to LP21 and LP02 with different dual-core fiber structures. It can be seen that the mode converter realizes LP01 to LP21 and LP02. The purity of LP21 is up to 98 %. The purity of LP02 is even up to 98 %, and the 3dB bandwidth is 21nm.