See-through display device and vehicle having see-through display device mounted thereon

A see-through display device comprising:

• a light source configured to emit light;
• a projection optical system configured to project image light generated from the light;
• a transparent substrate including an inner surface which faces an observer observing an image represented by the image light, and an outer surface opposite to the inner surface;
• a transmissive hologram including a first surface, which the image light enters from the projection optical system, a second surface opposite to the first surface, and a first interference fringe which allows the image light to propagate from the first surface to the second surface;
• wherein the hologram is supported on the inner surface or between the inner and outer surfaces,
• wherein the outer surface causes Fresnel reflection of the image light deflected by the first interference fringe,
• wherein the image light is incident on the outer surface as S-polarized light,
• wherein an emission angle of the image light emitted from the outer surface is larger than an incidence angle of the image light incident on the inner surface,
• wherein the first interference fringe is recorded by two-light flux interference of object light and reference light, which are incident on the first surface, and
• wherein the projection optical system is absent from an optical path of a main beam of the reference light which is used for recording the first interference fringe.