LOUVER, HEAD MOUNTED DISPLAY, AND OPTICAL DEVICE

A plate-shaped louver includes an incident surface on which light is incident from an optical element and an emission surface. The louver includes a plate-shaped base portion made of a light transmitting material and a light shielding portion arranged in contact with the light transmitting material inside the base portion. The light shielding portion includes a second surface and a first surface, the second surface being a surface on a side close to an outer edge of the plate-shaped base portion among surfaces of the light shielding portion, the first surface being a surface on an opposite side of the second surface. The light shielding portion includes an inclined portion in which the second surface is inclined with respect to the first surface. A thickness of the inclined portion is configured to increase from a side of the incident surface toward a side of the emission surface.