Sketch the three lowest order modes in a planar waveguide like that of Fig. 2.8 with n1 = n3 A mode is propagating in a planar waveguide as shown with βm = 0.8 kn2. How many reflections at the n1 −...

Sketch the three lowest order modes in a planar waveguide like that of Fig. 2.8

with n1 = n3

A mode is propagating in a planar waveguide as shown with βm = 0.8 kn2.

How many reflections at the n1 − n2 interface does the ray experience in traveling a distance of 1 cm in the z direction?