Light source device and projector

A light source device comprising:

• a light source section configured to emit a first light beam which has a first wavelength band and includes light polarized in a first polarization direction and light polarized in a second polarization direction different from the first polarization direction;
• an optical element which is configured to transmit the first light beam entering the optical element from the light source section along a first direction and polarized in the first polarization direction toward the first direction, and is configured to transmit the first light beam polarized in the second polarization direction toward the first direction;
• a polarization split element which is disposed at the first direction side of the optical element, which is configured to transmit the first light beam entering the polarization split element along the first direction from the optical element and polarized in the first polarization direction toward the first direction, and which is configured to reflect the first light beam polarized in the second polarization direction toward a second direction crossing the first direction;
• a wavelength conversion element which is disposed at the second direction side of the polarization split element, which is configured to perform wavelength conversion on the first light beam entering the wavelength conversion element along the second direction from the polarization split element, and polarized in the second polarization direction, and which is configured to emit a second light beam having a second wavelength band different from the first wavelength band toward a third direction as an opposite direction to the second direction;
• a diffusion element which is disposed at the first direction side of the polarization split element, and which is configured to diffuse the first light beam entering the diffusion element along the first direction from the polarization split element, and which is configured to emit the first light beam diffused toward a fourth direction as an opposite direction to the first direction;
• a first color separation element which is disposed at the third direction side of the polarization split element, and which is configured to separate light emitted from the polarization split element into a third light beam having the first wavelength band and a fourth light beam having the second wavelength band;
• and
• a second color separation element which is disposed at the third direction side of the optical element, and which is configured to separate light emitted from the optical element into a fifth light beam having a third wavelength band different from the second wavelength band, and a sixth light beam having a fourth wavelength band different from the second wavelength band and the third wavelength band, wherein
• the polarization split element transmits the second light beam polarized in the first polarization direction toward the third direction and reflects the second light beam polarized in the second polarization direction toward the fourth direction, and
• the optical element reflects the second light beam which enters the optical element along the fourth direction from the polarization split element and which is polarized in the second polarization direction toward the third direction.