Method to estimate surface heat transfer coefficient of solid-state laser

This article proposes a simple method using a false crystal (316L steel) to estimate the surface heat transfer coefficient of solid-state laser. First we set a low cooling water temperature, measure the temperature evolution of outlet water and the false crystal with two thermal couples, and then we calculate temporal evolution of temperature with arbitrary heat transfer coefficient using finite element analysis. By searching the lowest least square difference between measurement and simulation, heat transfer coefficient is estimated finally. The impact of heat transfer coefficient in rep-rated and high-energy laser design is also presented.