By Long-Sheng Ma, East China Normal University
In the past years, optical atomic clocks have obtained very significant progress with fractional instability and uncertainties of 10-18 level. Using optical clocks, scientists can search for the possible variations of fundamental constant, make a new definition of the unit of time and the application of relativistic geodesy. All this applications need precise transfer optical clock frequency to cover optical and microwave region without degrading their stability, accuracy and coherence. The recent results of optical frequency transfer at East China Normal University will be presented.