Liñares Beiras, JesúsPrieto Blanco, XesúsMontero Orille, CarlosMoreno de las Cuevas, Vicente2024-04-102024-04-102016Jesús Liñares, Xesús Prieto-Blanco, Carlos Montero-Orille, and Vicente Moreno, "Spatial mode multiplexing/demultiplexing by Gouy phase interferometry," Opt. Lett. 42, 93-96 (2017)1539-4794http://hdl.handle.net/10347/33479We present a theoretical study about spatial mode multiplexing/demultiplexing (mux/demux) without theoretical losses by means of interferometry with selective control of the Gouy phase of optical beams, that is, Gouy phase interferometry (GPI). Different Gouy phase values can be obtained by inserting appropriate optical systems at each arm of an interferometer. Thus, spatial mode mux/demux operations of strategic interest in optical communications with few-mode optical fibers are implemented by means of constructive interference and regardless of the parity and separability of the optical beams. Consequently, unachievable mux/demux by interferometry based on image inversion methods becomes possible with GPI. This kind of operation can also be interesting for optical sensors, optical metrology, image processing, and so on.eng© 2016 Optica Publishing Group. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited. Attribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/InterferenceMultiplexingFiber optics communicationsGradient-index lensesjournal article10.1364/OL.42.000093open access