Optical Communication Using Linear Sums of Optical Receiver Modes: Proof of Concept

We demonstrate the feasibility of an optical communication system that transmits linear sums of optical receiver modes (ORMs) as optical signals called ORM signals. The ORMs are inherent modes of conventional direct-detection optical receivers for wavelength-division multiplexing systems. Two lowest order ORMs are used to build ORM signals having distinct received voltage waveforms from each other. The optical receiver used has a Fabry-Perot filter as its optical filter and a fourth-order Bessel filter as its electrical filter. With these filters, corresponding ORMs are evaluated numerically and the ORM signals are generated using digital-to-analog converters. The received voltage waveforms after the receiver electrical filter are in good agreement with our analysis.