ارجو من المهندسين المختصين الاجابة على هذه الاسئلة الثلاث باقصى سرعة ولكم جزيل الشكر.
1) A graded index fiber has a core with a parabolic refractive index profile which has a
diameter of 60μm.the fiber has numerical aperture of 0.4.estimate the total number of
guided modes propagating in the fiber when it is operating at a wavelength of 2μm.
2) Determine the cutoff wavelength for a step index fiber to exhibit single mode
operation when the core refractive index and radius are 2.46 and 5.6μm, respectively,
with the relative index difference being 0.35%.
3) When the mean optical power launched into an 10km length of fiber is 150μw, the
mean optical power at the fiber output is 5μw.determine the followings:
a. The overall signal loss in decibel through the fiber assuming no connecters or splices.
b. The signal attenuation per kilometer for the fiber.:a45: