Focusing characteristics of a 4 πparabolic mirror light-matter interface Lucas Alber, Martin Fischer, Marianne Bader, Klaus Mantel, Markus Sondermann and Gerd Leuchs J. Eur. Opt. Soc.-Rapid Publ., 13 1 (2017) 14 Published online: 01 May 2017 DOI: 10.1186/s41476-017-0043-y