Kramers-Kronig coherent receiver

We review the principles underpinning the Kramers-Kronig (KK) receiver operation and its various implementations. These include direct-detection based schemes, where the information-carrying signal is transmitted along with a CW field that is necessary for the implementation of the KK algorithm, as well as other schemes, where the CW is added at the receiver, owing to the availability of a local oscillator. Polarization-multiplexing with the KK receiver will also be discussed. Finally, an up-to-date review of the experimental implementations of KK transceiver solutions will be presented.