Light source device and projector

A light source device comprising:

• a light emitting section configured to emit first light having a first wavelength band;
• a wavelength conversion layer having a first surface which the first light enters, and a second surface different from the first surface, and configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band, and emit the second light and another part of the first light from the second surface;
• and
• a polarization split element which is disposed so as to be opposed to the second surface of the wavelength conversion layer, and is configured to reflect third light having the first wavelength band and a first polarization direction and emitted from the second surface, transmit fourth light having the first wavelength band and a second polarization direction different from the first polarization direction and emitted from the second surface, reflect fifth light having the second wavelength band and the first polarization direction and emitted from the second surface, and transmit sixth light having the second wavelength band and the second polarization direction and emitted from the second surface, wherein
• light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer, and light intensity of light having the second polarization direction out of the first light entering the wavelength conversion layer, and
• the third light reflected by the polarization split element enters the wavelength conversion layer from the second surface of the wavelength conversion layer to be converted into the second light.

A light source device comprising:

• a light emitting section configured to emit first light having a first wavelength band;
• a wavelength conversion layer having a first surface which the first light enters, and a second surface different from the first surface, and configured to convert a part of the first light into second light having a second wavelength band different from the first wavelength band, and emit the second light and another part of the first light from the second surface;
• and
• a polarization split element which is disposed so as to be opposed to the second surface of the wavelength conversion layer, and is configured to reflect third light having the first wavelength band and a first polarization direction and emitted from the second surface, transmit fourth light having the first wavelength band and a second polarization direction different from the first polarization direction and emitted from the second surface, reflect fifth light having the second wavelength band and the first polarization direction and emitted from the second surface, and transmit sixth light having the second wavelength band and the second polarization direction and emitted from the second surface, wherein
• light intensity of the fourth light is controlled by controlling light intensity of light having the first polarization direction out of the first light entering the wavelength conversion layer, and light intensity of light having the second polarization direction out of the first light entering the wavelength conversion layer, and
• the fifth light reflected by the polarization split element enters the wavelength conversion layer from the second surface of the wavelength conversion layer, and a part of the fifth light entering the wavelength conversion layer from the second surface is converted into the sixth light.