Single vector mode transmission in hollow-core photonic bandgap fiber based on surface mode coupling effect

Relying on the long-distance mode retention capability of hollow core fibers (HCFs) to achieve particle capture and advancement has become a breakthrough in optical tweezers research. This first requires the HCF to get a balance long distance and pure mode. However, the unique light guide mechanism and complex drawing process make it a difficult question to decrease the number of the allowed modes. In this paper, a hollow core photonic bandgap fiber (HC-PBF) that only supports pure TE₀₁ mode over 100 nm bandwidth covering the C + L band with the lowest loss of 10.2 dB/km is proposed. The core wall is used as the only control variable to control the coupling position of surface modes (SMs) in the bandgap to filter unwanted modes and achieve stable single-mode transmission in the fiber. The thick core wall allows the fiber to be crimped to a radius of 0.25 mm. Moreover, characteristics such as mode conversion and manufacturing tolerances are also discussed.