Light source device and projector

A light source device comprising:

• a blue laser emitting element;
• a red laser emitting element configured to emit light in a predetermined wavelength band;
• a light combining element configured to combine light from the blue laser emitting element and the light from the red laser emitting element with each other;
• a diffusely reflecting element configured to diffuse and reflect apart of the light from the blue laser emitting element and the light from the red laser emitting element;
• a phosphor excited by a part of the light from the blue laser emitting element to emit fluorescence including red fluorescence and green fluorescence;
• a polarization splitting/combining element disposed in a posterior stage of the light combining element, and having a polarization split function with respect to a first red fluorescence component corresponding to the predetermined wavelength band out of the red fluorescence, the light from the red laser emitting element, and the light from the blue laser emitting element;
• and
• a first wave plate disposed between the polarization splitting/combining element and the diffusely reflecting element, wherein
• the polarization splitting/combining element
• guides a blue first polarization component obtained by performing polarization split on the light from the blue laser emitting element, and the light from the red laser emitting element to the diffusely reflecting element, and guides a blue second polarization component obtained by performing polarization split on the light from the blue laser emitting element to the phosphor,
• emits, in one direction,
• red diffused light obtained by converting the light from the red laser emitting element via the diffusely reflecting element and the first wave plate into a different polarization state,
• blue diffused light obtained by converting the blue first polarization component via the diffusely reflecting element and the first wave plate into a different polarization state,
• a red polarization split component obtained by performing polarization split on the first red fluorescence component, and
• a principal fluorescence component obtained by removing the first red fluorescence component from the fluorescence,
• to combine the red diffused light, the blue diffused light, the red polarization split component, and the principal fluorescence component with each other to generate illumination light.