Path integral for non-paraxial optics Maria Chiara Braidotti, Claudio Conti, Mir Faizal, Sanjib Dey, Lina Alasfar, Salwa Alsaleh and Amani Ashour EPL, 124 4 (2018) 44001 Published online: 14 December 2018 DOI: 10.1209/0295-5075/124/44001