Phase retarders with variable angles of total internal reflection.
Results for three λ/4 phase retarders are reported. One of them is achromatic to within ± 0.06° of 90° in the visible region. It is shown that, under certain conditions, oblique incidence on the entrance face of total internal reflection phase retarders can greatly improve the achromaticity.
Nagib
N N
NN
E-Bahrawy
M S
MS