A.2km B.1km C.1.5km D.0.5km
A.5.0m B.3.0m C.5.5m D.7.5m
A.數(shù)值孔徑NA B.模場(chǎng)直徑 C.光纖幾何參數(shù) D.光纖截止波長(zhǎng)