Fast radio bursts (FRBs) are intense transient millisecond radio signal with large dispersion measures (DM). Radio signal, which propagates through cold plasma, is dispersed as frequency square. After subtracted from the effect from galactic interstellar medium, the FRB's DMs are still large. This can be interpreted as FRBs have an extragalatic origin.As DM is related to the free electron content along the line of sight, FRBs are expected to be use as a universe probe. Until now, only 17 FRB have been detected. Only FRB 150418 has been proposed with an optical counterpart by Subaru telescope (Keane, 2016). FRB121102 has been found to be repeating 10 times since 2012. In this work, we have calculated luminosity function from current FRB population, and result from the optical follow up of FRB 150418 by Thai National Telescope.
Keywords:Cosmology, Radio Astrophysics.