Ultralow bending-loss micro-structured fiber with large-mode-area

A novel design of photonic crystal optical fiber device with center-doped capillaries is proposed in this paper. A high leakage loss ratio (3551.41) between the high-order modes (HOMs) and the fundamental mode (FM) can be achieved at wavelength 1.064 mu m, which is beneficial for robust single-mode operation and enhancing the transverse mode instabilities. The simulation shows that the effective mode area of the proposed fiber can be reached 806.24 mu m2 at bend radius of 10 cm. Besides, the FM bending loss can be reached 6.42 x 10-4 dB/m at the diameter of centerdoped capillaries of 3 mu m. The proposed fiber has improved single-mode operation at a practically allowable bending radii of 5-10 cm. Compared with recent notable designs, the effective mode area and the FM bending loss of FM are improved, even in smaller bend radius.