本文报道了利用棱镜-光纤耦合器,通过测量耦合角或m-线的位置,从而得到光纤标量模传输系数β(mn)的方法。测得的β(mn)值与用标量近似法算得的β(mn)相差很小。

In the paper it is reported that using a prism-fiber coupler, the propagation coefficient βmn for scalar modes travelling in optical fiber can be determined by measuring coupling angles or positions of m-lines. Each scalar mode can be excited by varying the coupling angle. The so-called m-line corresponding to each scalar mode is coupled out of an output prism. Its characteristics are different from those of the m-line coupled out of a planar waveguide. The degeneration of βmn is shown on the m-line photograph. A good agreement is obtained between, the measured and calculated values of βmn.