Modem electronic industry takes many efforts to reduce the power dissipated on single chip and as it was reported, up to 50% of this total power is caused by Clock Distribution Network (CDN). What is more, it is getting worse when speed increases. That is why this matter is investigated and new solutions are under deep research. Optical signaling seems to be very promising here, because ofbroad bandwidth, noise conditions etc. This paper discusses the Electrical Clock Distribution Networks (ECDN) versus Optical Clock Distribution Networks (OCDN) and contains short summary of some typical, published solutions of the circuits of the optical receivers. It shows the commonly used topologies and technologies of the optical receiver circuits and tries to points out their strong and weak sides.