Abstract: A method, apparatus and system for polarization conversion and recycling by using a half-pyramid shaped reflector with multiple reflective surfaces, or said reflector assembly, to obtain a desirable polarization rotation effect. The disclosed half-pyramid reflector comprises a plurality of reflective surfaces, which are formed so that an incoming beam passing perpendicularly through the entrant surface is reflected three times inside the device and leaves the exit surface with the direction of polarization being rotated 90 degrees. The preferred embodiments of polarization:conversion systems using the invented apparatus are included. Without employing any waveplate component, the disclosed system is not sensitive to wavelength variations of the light source, temperature changes, and polarization alignment errors.

Abstract: A method, apparatus and system for polarization conversion and recycling by using a half-pyramid shaped reflector with multiple reflective surfaces, or said reflector assembly, to obtain a desirable polarization rotation effect. The disclosed half-pyramid reflector comprises a plurality of reflective surfaces, which are formed so that an incoming beam passing perpendicularly through the entrant surface is reflected three times inside the device and leaves the exit surface with the direction of polarization being rotated 90 degrees. The preferred embodiments of polarization conversion systems using the invented apparatus are included. Without employing any waveplate component, the disclosed system is not sensitive to wavelength variations of the light source, temperature changes, and polarization alignment errors.