Supporting Information: Optical Properties of Saturated and Unsaturated Carbonyl Defects in Polyethylene Guido Roma, *, Fabien Bruneval, and Layla Martin-Samos , DEN-Service de Recherches de Métallurgie Physique, CEA, Université Paris-Saclay, F-91191 Gif sur Yvette, France, and Materials Research Laboratory, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia E-mail: guido.roma@cea.fr * To whom correspondence should be addressed DEN-Service de Recherches de Métallurgie Physique, CEA, Université Paris-Saclay, F-91191 Gif sur Yvette, France Materials Research Laboratory, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia CNR-IOM DEMOCRITOS, Istituto Officina dei Materiali, c/o SISSA Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste Italy S1