A bend -resistant double -trench fiber with leakage channels for HOMs suppression

摘要

A double trench fiber with parabolic-profile core (PPDTF) and leakage channels (LC-PPDTF) is proposed in this paper. Due to the leakage channels, the loss of the higher-order modes (HOMs) is enhanced dramatically while the fundamental mode is hardly affected. High loss ratio (400) of the higher-order modes to the fundamental mode is achieved in a wide range of bend radius and bend orientation at wavelength 1.06 mu m. The highest loss ratio reaches 2211, which is 62% higher than that of ordinary PPDTF without leakage channels. A large mode area of more than 450 mu m(2) hardly varies with the bend radius is realized. The fiber with a 100 mu m core diameter and a mode area over 1284 mu m(2) is also presented. This fiber design shows great potential in compact high- power fiber lasers and amplifiers.