Nemoto S, Yip G L, Farnell G W
Appl Opt. 1975 Jul 1;14(7):1543-8. doi: 10.1364/AO.14.001543.
The launching efficiencies of the HE(1m) modes and the over-all launching efficiency are calculated for the cases in which a self-focusing optical fiber is excited axially by a TEM(0n) beam mode or by a beam consisting of several beam modes. It is shown that, when the fiber is excited by a TEM(00) mode whose spot size s is very large compared with the characteristic spot size s(0) of the fiber, the HEM(1m) modes are almost equally excited and that, if s is matched to s(0), the over-all launching efficiency is nearly 100%. The over-all launching efficiency as well as the launching efficiencies of the HE(1m) modes decrease considerably when the fiber is excited by a beam containing the TEM(01) mode that is out of phase with the TEM(00) mode. The effect of the off-axis excitation by a TEM(00) mode on the over-all launching efficiency is also examined.
计算了在自聚焦光纤由TEM(0n)光束模式或由几种光束模式组成的光束轴向激发的情况下，HE(1m)模式的发射效率和总体发射效率。结果表明，当光纤由光斑尺寸s与光纤特征光斑尺寸s(0)相比非常大的TEM(00)模式激发时，HEM(1m)模式几乎被同等激发，并且，如果s与s(0)匹配，则总体发射效率接近100%。当光纤由与TEM(00)模式异相的包含TEM(01)模式的光束激发时，总体发射效率以及HE(1m)模式的发射效率会显著降低。还研究了TEM(00)模式的离轴激发对总体发射效率的影响。
