*10.2-4 Propagation Constants and Wavevector (Step-Index Fiber). A step-index fiber of radius a = 20 µm and refractive indices n, = 1.47 and ng = 1.46 operates at A, = 1.55 µm. Using the quasi-plane wave theory and considering only guided modes with / = 1: (a) determine the smallest and largest propagation constants; (b) for the mode with the smallest propagation constant, determine the radii of the cylin- drical shell within which the wave is confined, and determine the components of the wavevector k at r = 5 µm. *10.2-5 Propagation Constants and Wavevector (Graded-Index Fiber). Carry out the same cal- culations as in Prob. 10.2-4, but for a groded-index fiber with parabolic profile (p = 2).

10.2-4 Propagation Constants and Wavevector (Step-Index Fiber). A step-index fiber of radius a = 20 µm and refractive indices n, = 1.47 and ng = 1.46 operates at A, = 1.55 µm. Using the quasi-plane wave theory and considering only guided modes with / = 1: (a) determine the smallest and largest propagation constants; (b) for the mode with the smallest propagation constant, determine the radii of the cylin- drical shell within which the wave is confined, and determine the components of the wavevector k at r = 5 µm. 10.2-5 Propagation Constants and Wavevector (Graded-Index Fiber). Carry out the same cal- culations as in Prob. 10.2-4, but for a groded-index fiber with parabolic profile (p = 2).