A grating situated on a planar waveguide can act as a 180◦ reflector for the waves within the guide. If the propagation constant of the guided mode is β = 1.582 k and λ0 = 0.6328 μm, find the smallest...

A grating situated on a planar waveguide can act as a 180◦ reflector for the

waves within the guide. If the propagation constant of the guided mode is

β = 1.582 k and λ0 = 0.6328 μm, find the smallest grating spacing A that will