Light source apparatus and projector

A light source apparatus comprising:

• a light source configured to emit first light having a first wavelength band;
• a wavelength conversion layer having a light incident surface, the wavelength conversion layer being configured to convert the first light which is incident on the light incident surface into second light having a second wavelength band different from the first wavelength band;
• a substrate having a support surface configured to support the wavelength conversion layer;
• a first optical member including a first optical layer configured to transmit the first light emitted from the light source and reflect the second light, the first optical layer facing the support surface;
• a second optical member having a second optical layer configured to reflect the first light and the second light, the second optical layer intersecting with the support surface and the first optical layer;
• a third optical member having a third optical layer configured to reflect the first light and the second light, the third optical layer intersecting with the support surface and the first optical layer and facing the second optical layer;
• and
• a fourth optical layer configured to cover an aperture formed by the substrate, the first optical member, the second optical member, and the third optical member, the fourth optical layer being configured to reflect the first light and transmit the second light,
• wherein the first light emitted from the light source is polarized in a first direction,
• the first optical member includes a fifth optical layer provided on a side facing the light source, the fifth optical layer being configured to transmit the first light polarized in the first direction,
• the first optical layer is provided on a side facing the wavelength conversion layer in the first optical member and is configured to reflect part of the first light emitted from the wavelength conversion layer,
• the fifth optical layer is configured to reflect the first light polarized in a second direction different from the first direction,
• a first area of the light incident surface of the wavelength conversion layer is greater than a second area of a light incident region, of the light incident surface, on which the first light is incident, and
• the second area of the light incident region is greater than a third area of the aperture.