采用平面波展开法研究了空芯光子晶体光纤 (HC-PCF) 的导波模式特性。结果表明,在包层带隙范围内, 当导波模的纵向相位传播常数[EQUATION]满足一定条件时,才能在 HC-PCF 纤芯中形成稳定的基模传输;并且,纤芯基模的模场分布与光波长有关, 当光波长位于纤芯基模传输曲线中央时,光波能量被很好地约束在纤芯中,而当光波长位于纤芯基模传输曲线的上下边沿时, 光波能量将向包层中漏泄。

The guided-mode properties of hollow-core photonic crystal fibers (HC-PCFs) were studied with the plane-wave expansion method (PWE). The simulation results show that, for a given wavelength in the photonic band-gap of the cladding structure, stable fundamental core mode may be obtained only with specific vertical phase propagating constants. Moreover, the mode field distributions of fundamental core modes depend on the wavelength. When the wavelength is right at the center of the fundamental core mode transmitting curve, the mode field may be confined in the air-core perfectly. When the wavelength is near the edges of the fundamental core mode transmitting curve, the energy of guided-wave core modes may leak into the cladding of HC-PCF.