Optical fiber communication 122021/2/19 3、横向位移d( lateral offset) 2<2 Z=7∈xp( 2 7=7 O) 12 /2 B、s1=s2=s exp S T=1e de=s L(aB)=4.34(1-12 Copyright Wang Yan 2021/2/19 Optical fiber communications A、 B、s1=s2=s T=1/e de=s (( ) ) 2 0 2 2 1 2 0 1 2 2 2 1 2 2 exp( ) / / 2 d T T s s T T e d de s s = − + = = = +       = − 2 exp ( ) s d T ( 0) T0 = 2 ( ) 4.34( ) s d L dB = 3、横向位移d（lateral offset）