Withington Stafford, Yassin Ghassan
Cavendish Laboratory, University of Cambridge, UK.
J Opt Soc Am A Opt Image Sci Vis. 2002 Jul;19(7):1376-82. doi: 10.1364/josaa.19.001376.
A procedure is described for calculating the power coupled between partially coherent waveguide fields that are in different states of coherence. The method becomes important when it is necessary to calculate the power transferred from a distributed source S to a distributed load L through a length of multimode metallic, or dielectric, waveguide. It is shown that if the correlations between the transverse components of the electric and magnetic fields of S and L are described by coherence matrices M and M', respectively, then the normalized average power coupled between them is (eta) = Tr[MM']/Tr[M]Tr[M'], where Tr denotes the trace. When the modal impedances are equal, this expression for the coupled power reduces to an equation derived in a previous paper [J. Opt. Soc. Am. A 18, 3061 (2001)], by use of thermodynamic arguments, for the power coupled between partially coherent free-space beams.
描述了一种用于计算处于不同相干态的部分相干波导场之间耦合功率的方法。当需要计算从分布式源S通过一段多模金属或介质波导传输到分布式负载L的功率时，该方法变得很重要。结果表明，如果源S和负载L的电场和磁场横向分量之间的相关性分别由相干矩阵M和M'描述，那么它们之间耦合的归一化平均功率为(eta) = Tr[MM']/Tr[M]Tr[M']，其中Tr表示迹。当模式阻抗相等时，这种耦合功率的表达式简化为先前一篇论文[《美国光学学会志A》18, 3061 (2001)]中通过热力学论证得出的关于部分相干自由空间光束之间耦合功率的方程。
