3.2 For silica, compute the magnitude of the pulse spread per unit length if the source wave- length is 0.85 m. The spectral width is 30 nm. Repeat for a spectral width of 2 nm. Problems 91 3.3 Repeat Problem 3.2 for a source wavelength of 1.55 m. Assume that the material dis- 3.4 Use the results of Problems 3.2 and 3.3 to compute the maximum data rates and modula- person is M =-20 ps/(nm km). tion frequencies. Give your answers for 100 m, 1 km, and 10 km and for RZ and NRZ codes. 3.5 Compute the propagation constant in air and in glass if the free-space wavelength is 0.82 m