<title>Influence of aerosols and optical turbulence strength on laser beam widening in the atmosphere</title>

On a basis of a Monte Carlo simulation model, the atmospheric aerosol contributions to laser beam widening for a horizontal propagation path at various elevations is estimated and compared with beam widening caused by turbulence. It is shown that the beam widening caused by atmospheric aerosols is significant, often even more significant than that caused by turbulence.