Source of Entangled Photons (image) Louisiana State University Share Print E-Mail Caption Source of entangled photons. A lens is used to focus the pump beam onto the non-linear crystal, the generated entangled photons are collected by a second lens and then sent to a polarizing beam splitter. This is utilized to direct entangled photons to different ports of the source. Photons with different polarizations emerge through different output ports. The red laser in the polarizing beam splitter is utilized for alignment purposes. Credit Elsa Hahne, LSU Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.