空气中波长为1.3μm的近红外均匀平行光通过直径为50mm，焦距为100mm的凸透镜后，在焦平面光斑的直径为 ()A、0.828mmB、6.144mmC、0.828μmD、6.144μm - 查题网

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空气中波长为1.3μm的近红外均匀平行光通过直径为50mm，焦距为100mm的凸透镜后，在焦平面光斑的直径为 ()
A、0.828mm
B、6.144mm
C、0.828μm
D、6.144μm

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光纤通信

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