Kramers-Kronig（KK） receiver can retrieve the phase information from the intensity information of an optical signal satisfying the minimum-phase condition. This enables KK receiver to overcome the limitation that single photodetector can only detect the intensity information of an optical signal

thus it has attracted a great deal of attention. KK receiver can compensate for the distortion due to fiber chromatic dispersion and reduce the required carrier-to-signal power ratio in an optical transmission system

significantly increasing the channel capacity and transmission distance. Since only a single-end photodetector is used

it reduces the implementation cost of a coherent optical receiver. This makes KK receiver a very promising candidate technology for the cost-sensitive intra-datacenter interconnections. However

this receiver has a couple of technical issues hindering its practicality. In this paper

the principles and applications of KK receiver

as well as its technical issues and solutions are discussed. Meanwhile

the challenges in the practical implementation of this receiver are investigated as well. Finally

the prospect of related research is discussed briefly.