Lighting apparatus and projection-type image display apparatus

A lighting apparatus comprising:

• a light source generating a first color component light;
• a separation element configured to partially transmit the first color component light, partially reflect the first color component light, and transmit a second color component light different from the first color component light at a certain moment;
• an illuminant excited by the first color component light transmitted through the separation element to generate the second color component light;
• and
• an optical system configured to combine the first color component light made incident on the separation element from the light source and reflected by the separation element with the second color component light made incident on the separation element from the illuminant and transmitted through the separation element, wherein
• the separation element is configured to have variable transmittance and reflectance with respect to the first color component light, and
• the first color component light generated by the light source is linearly polarized,
• the separation element includes
• a half-wave plate rotatably disposed, the half-wave plate rotating a polarization plane of the first color component light over a predetermined angle, and
• a polarization beam splitter configured to partially transmit and partially reflect the first color component light depending on polarization of the first color component light.