Optimal power of laser beams propagating from the ground through the atmosphere to space orbits

It is shown that, when a high-power laser beam propagates from the ground through the atmosphere to space orbits, there is an optimal beam power that maximizes the target intensity due to self-focusing effect in the atmosphere, even if the atmospheric extinction exists. The B integral is an important parameter to describe self-focusing effect quantitatively. It is found that the value of B integral corresponding to optimal beam power is a constant. Based on this characteristic of the optimal B integral and the concept of the equivalent atmospheric extinction coefficient proposed in this paper, we derive the analytical formula of the optimal beam power, which presents an effective design rule to optimize the target intensity. In addition, it is shown that the optimal beam power increases as the initial beam radius, the wavelength, the atmospheric extinction coefficient, and the aerosol scale height increase. •An effective design rule is presented to optimize the target intensity.•It is found that the value of B integral corresponding to optimal beam power is a constant.•A concept of the equivalent atmospheric extinction coefficient is proposed.•The analytical formula of the optimal beam power is derived.•There is an optimal power that maximizes the target intensity due to self-focusing effect.