With the availability of small arc size high intensity discharge lamps a new polarization recovery system using polarization recycling in a light pipe is made possible. Combining light integration/homogenization with polarization recovery in an integrator rod leads to cost reduction and smaller light engines. The polarization recovery light pipe utilizes a reflective polarizer that works at normal incidence at its exit face and a high-reflective mirror with a transparent circular aperture at the entrance face. The reflected linearly polarized light is recycled by rotating its polarization by 90 degree(s) during one round-trip in the integrator rod. Different possibilities for achieving this polarization rotation, including retarders and phase control coatings are investigated. As much as 70% of the rejected polarized light can be recaptured with this system.

Date Published: 26 April 2002
PDF: 8 pages
Proc. SPIE 4657, Projection Displays VIII, (26 April 2002); doi: 10.1117/12.463789

Published in SPIE Proceedings Vol. 4657:
Projection Displays VIII
Ming Hsien Wu, Editor(s)