title: Test of mode-division multiplexing and demultiplexing in free-space with diffractive transformation optics.
abstract: In recent years, mode-division multiplexing (MDM) has been proposed as a promising solution in order to increase the information capacity of optical networks both in free-space and in optical fiber transmission. Here we present the design, fabrication and test of diffractive optical elements for mode-division multiplexing based on optical transformations in the visible range. Diffractive optics have been fabricated by means of 3D high-resolution electron beam lithography on polymethylmethacrylate resist layer spun over a glass substrate. The same optical sequence was exploited both for input-mode multiplexing and for output-mode sorting after free-space propagation. Their high miniaturization level and efficiency make these optical devices ideal for integration into next-generation platforms for mode-division (de)multiplexing in telecom applications.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Ruffato
authors.forename: Michele
authors.initials: M
authors.lastname: Massari
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Parisi
authors.forename: Filippo
authors.initials: F
authors.lastname: Romanato