All-Glass Single-Mode Leakage Channel Microstructured Optical Fibers with Large Mode Area and Low Bending Loss

The paper presents the results of theoretical and experimental studies of all-glass leakage channel microstructured optical fibers (MOFs) with a large mode area and low bending losses. These MOFs contain two layers of fluorine-doped silica glass elements with a reduced refractive index, different diameters, and different distances between them. A numerical analysis of the properties of these MOFs was performed using the finite element method. The leakage losses for the fundamental and higher-order modes were calculated in the spectral range from 0.65 mu m to 1.65 mu m. Simulation results show that the proposed MOF design allows for single-mode guidance in the spectral range from 0.92 mu m to 1.21 mu m with a bending radius of down to 0.08 m. The measured losses of the fabricated MOF with a core diameter of 22.5 mu m and a bending radius of 0.1 m were less than 0.1 dB/m in the spectral range from 0.9 mu m to 1.5 mu m. It is demonstrated that the segments of this MOF longer than 5 m are single-mode.