Numerical Simulation Of Hollow-Core Fibers With Cobweb Cladding Structer

Hollow-core fiber is becoming a new focus of novel fiber research, as wecan see from the name the core of the fiber is made up of air and lightpropagates in it. So far, there are three classes of hollow-core fibers, they areBragg fiber, photonic bandgap fiber and ring-structured Bragg fiber, they allconfine light in their hollow core through photonic bandgap effect. These three classes of hollow-core fibers more or less have somedifficulties to fabricate, therefore, our research group proposed a cobwebcladding structure hollow-core fiber after taking into account all aspects of theabove three classes of hollow-core fiber, it can be fabricated with only onematerial and solve the problem of structure support. In this paper, we usefull-vector plane-wave method to analyze the characteristics of the bandgap ofcobweb cladding structure at large, and indicate the range of the width of highindex layer. The effect of the air layer width and the different high indexmaterial on the fundamental mode of the fiber is analyzed. Based on thecalculation, we discuss the tolerance of structure parameters, and give theguideline of designing the cobweb cladding structure. The possibility ofomnidirectional reflector made of PMMA and air is also discussed. Finally, weintroduce compact 2-D finite-difference time-domain method to calculate thefield distribution of cobweb cladding structure hollow-core fiber, and discuss towhat extent the supporting strips affected the mode losses of the fiberqualitatively.