title: Communication modes in large-aperture approximation.
abstract: Simplified versions of the communication modes in the Fresnel domain are derived when the system apertures are large. The approximate modes, which are in the form of spherical waves and sinc functions with a spherical curvature, give physical insight into the communication modes approach and the basic limits of free-space optical communication systems. They also show that Gabor's information theory is readily derived from the communication modes.
authors.affiliation: National University of Ireland, Galway, Department of Experimental Physics, Applied Optics. anna.burvall@nuigalway.ie
authors.forename: Anna
authors.initials: A
authors.lastname: Burvall
authors.forename: Per
authors.initials: P
authors.lastname: Martinsson
authors.forename: Ari T
authors.initials: AT
authors.lastname: Friberg