Optical device, light source device, and projector

A light source device comprising:

• an optical device which includes a light-emitting layer structure constituted of a first light-emitting layer and a second light-emitting layer, and a wavelength selection unit;
• and
• an energy generation unit, wherein
• the wavelength selection unit is disposed on one side of the light-emitting layer structure,
• the first light-emitting layer emits light having a first wavelength region,
• the second light-emitting layer emits light having a second wavelength region based on light emitted from the first light-emitting layer, and
• the wavelength selection unit allows a part of light having the first wavelength region emitted from the light-emitting layer structure to pass through, returns the remaining light to the light-emitting layer structure, and allows light having the second wavelength region to pass through.

A projector comprising:

• a light source device equipped with an optical device which includes a light-emitting layer structure constituted of a first light-emitting layer and a second light-emitting layer and a wavelength selection unit, and an energy generation unit;
• an illumination optical system;
• an image forming unit;
• and
• a projection optical system, wherein
• the wavelength selection unit is disposed on one side of the light-emitting layer structure,
• the first light-emitting layer emits light having a first wavelength region,
• the second light-emitting layer emits light having a second wavelength region based on light emitted from the first light-emitting layer,
• the wavelength selection unit allows a part of the light having the first wavelength region emitted from the light-emitting layer structure to pass through, returns the remaining light to the light-emitting layer structure, and allows light having the second wavelength region to pass through,
• an image is formed by the image forming unit using light passed through the wavelength selection unit, and
• the image formed by the image forming unit is sent to the projection optical system.