We present a novel design of a superconducting nano-wire single photon detector (SNSPD). Detectors of this type provide visible and near infra-red photon counting on GHz rates with extremely low dark count. The proposed new design allows one to overcome the major drawback of the existing devices, namely low efficiency of light coupling to the SNSPD. The new approaches of resonant photonic cavity enhanced detection and in-line detector fabrication on a single mode optical fiber are discussed. We present theoretical model as well as initial experimental results on our route towards SNSPD with quantum efficiency over 98%.