Patent ID: 8136948

Claim:
An etendue maintaining polarization switching system comprising: a laser illumination system configured to provide polarized light along a first light path; a pivoted reflective element disposed in the first light path, the pivoted reflective element actuable to controllably and alternatively direct the polarized light in the first light path, without changing its polarization, along at least a second light path and a third light path; a rotation device and a driving device collectively configured to pivot the pivoted reflective element, the driving device being configured to provide the rotation device a driving signal configured to cause the rotation device to pivot the pivoted reflective element, wherein the pivoted reflective element includes an optical surface configured to slightly deform when the rotation device and the driving device pivot the pivoted reflective element; a reflective retarding system disposed in the third light path configured to change the polarized light into light having a different polarization and to reflect the light having the different polarization along the third light path; and a polarization combining device configured to combine light from the second light path with the light having the different polarization from the reflective retarding system in the third light path into a single light beam exhibiting a same or substantially a same etendue as the first light path.