Numerical analysis of thermal effects on laser beam propagation

This paper presents the numerical analysis about the thermal effects, produced by the high-energy laser in a beam control system, on the laser beam propagation. The propagation of laser is described by the paraxial wave equations, solved by the phase-screen technique and the FFT method. The thermal turbulence motion and the air density variation are governed by the complete Navier-Stokes equations, so that the variety factors could be in consideration. The Navier-Stokes equations are solved by using the LU-SGS factorization technique. The methods could be used for other kinds of aero-optical problems. The numerical results show that, with the additional initial thermal-phase, the energy concentration and the quality of the laser beam at far field would be prominently degraded for the typical situations.