Double negative curvature anti-resonance hollow core fiber

We report on a double negative curvature anti-resonance hollow core fiber, in which, the cladding is constituted of 6 large tubes and 6 small tubes arranged in a staggered pattern. The simulation shows that the loss of the fiber can reach or even exceed the loss of double-clad negative curvature anti-resonance hollow core fibers in short wavelength band, due to the staggered arrangement of two kind of tubes and the double negative curvature on the core boundary. The best single mode performance with a loss ratio as high as 100,000 between LP mode and LP mode is obtained due to simultaneously inhibited LP modes and LP modes in the fiber structure. The reason for loss oscillations in long wavelength band and the fabrication feasibility of proposed fiber are also discussed.