All-optical frequency upconversion of radio over fibre signal with optical heterodyne detection

An all-optical frequency upconversion of radio over fibre signal with an optical heterodyne detection that is based on the cross-phase modulation effect in a semiconductor optical amplifier is proposed. Optical IF signal that contains 155.52 Mbit/s differential phase shift keying signal at 2.5 GHz along with 24 GHz optical LO signal are transmitted over a 20 km-long single mode fibre and then frequency upconverted to 26.5 GHz at a remote base station by using an SOA Mach-Zehnder interferometer. Error-free frequency upconversion is experimentally demonstrated.