通过改变多孔光纤中的芯区面积、空气孔的直径和分布,可以灵活地设计其导波特性。利用耦合波方程分析了参量波长变换的基本原理,讨论了信号波长固定情况下相位失配和抽运波长之间的关系。对基于多孔光纤的参量波长变换的转换效率进行了数值模拟,并和实验测量的数据进行了比较,结果表明它们的结果相一致。采用15 m长的多孔光纤可以获得约10 nm的3 dB调谐带宽,最大转换效率约为-16 dB,并且采用较低色散斜率值的多孔光纤可以进一步增大调谐范围。因此,利用多孔光纤可以实现紧凑的波长变换器。

The guidance properties of the holey fiber are determined by the solid-silica core region and the size and pattern of air holes. The fundamental principle of parametric wavelength conversion is presented by the coupled-wave equations. The relation between phase mismatch and pump wavelength with a fixed signal wavelength is analyzed. Conversion efficiency of a holey fiber based parametric wavelength conversion is calculated by the numerical simulation and compared with the measured result, which indicates that numerical calculation is coincident with the experimental measurement. A maximum conversion efficiency of about -16 dB and a 3-dB tuning bandwidth of ～10 nm are achieved for a 15 m holey fiber, and the tuning range can be improved with lower dispersion slope. So a compact wavelength converter can be realized by utilizing a highly nonlinear holey fiber.