Influence of inner-arc curvature and number of cladding rings on confinement loss in a hypocycloid-shaped kagome hollow-core photonic crystal fiber

A hypocycloid-shaped hollow-core photonic crystal fiber is proposed and investigated numerically, taking account of the inhibited coupling mechanism for light guidance. The results show that the curvature of the internal arcs surrounding the core has a very significant impact on the confinement loss, whereas the number of cladding rings has only a weak influence. For an arc curvature of 1 with three cladding rings, a confinement loss of just ∼10 dB/km can be achieved for a bandwidth of 1000 nm covering the range from 1 to 2 μm.