Effect of thermal characteristics in laser transmitting channel on far-field beam quality

In this paper, the laser thermal effects, produced in the transmitting channel of a beam control system, are numerically analyzed. The laser propagation is governed by the paraxial wave equation, which is solved by the FFT method. The air density variation is calculated with the complete Navier-Stokes equations. The numerical tests are carried out for different wave length of laser and different absorption coefficients of air medium, in order to estimate the effects on the beam quality at far field. The results show that the laser thermal effects in the transmitting channel may largely reduce the concentration of laser energy at far field.