A rutile prism (np = 2.50) is used to couple light of vacuum wavelength λ0 = 0.9050 μm to the fundamental mode in a waveguide which has a refractive index ng = 2.09. Given that the phase constant of...

A rutile prism (np = 2.50) is used to couple light of vacuum wavelength

λ0 = 0.9050 μm to the fundamental mode in a waveguide which has a refractive index ng = 2.09. Given that the phase constant of the fundamental mode

is β0 = 1.44 × 105 cm−1 what angle γ must the input face of the prism make

with the waveguide surface and what angle φ must the optical beam within the

prism make with the waveguide surface in order to obtain the most efficient

coupling.