Optimising zero-order suppression in ion-exchanged phase gratings Carlos Montero-Orille, Héctor González-Núñez, Xesús Prieto-Blanco, Vicente Moreno, Dolores Mouriz, María C. Nistal and Jesús Liñares EPJ Web Conf., 238 (2020) 03006 Published online: 20 August 2020 DOI: 10.1051/epjconf/202023803006