US Patent 10960465 Light recycling for additive manufacturing optimization

A method and an apparatus pertaining to recycling and reuse of unwanted light in additive manufacturing can multiplex multiple beams of light including at least one or more beams of light from one or more light sources. The multiple beams of light may be reshaped and blended to provide a first beam of light. A spatial polarization pattern may be applied on the first beam of light to provide a second beam of light. Polarization states of the second beam of light may be split to reflect a third beam of light, which may be reshaped into a fourth beam of light. The fourth beam of light may be introduced as one of the multiple beams of light to result in a fifth beam of light.