Patent attributes
An optical device includes an optical guide adapted for propagating a light beam by successive total internal reflections and an injection device adapted for injecting the light beam into the optical guide via an injection section. A polarizing material is present between the optical guide and the injection device at the injection section. The injection device includes a prism and an assembly formed by a quarter-wave plate and curved mirror, the injection device being arranged so that a light beam reflected by the polarizing material in the direction of the curved mirror passes through the quarter-wave plate and is then reflected by the curved mirror in the direction of the polarizing material and passes through the quarter-wave plate again.