Spreading and M²-factor of elegant Hermite–Gaussian beams through non-Kolmogorov turbulence

Abstract

Using a non-Kolmogorov power spectrum, analytical expressions for the beam width, angular spread and M ²-factor of elegant Hermite–Gaussian (EHG) beams through non-Kolmogorov turbulence are derived. It is shown that the beam-width spreading, angular spread and M ²-factor of EHG beams through non-Kolmogorov turbulence depend on the non-Kolmogorov turbulence, i.e. on the generalised exponent parameter, , the inner scale, l ₀, and the outer scale, L ₀, at a sufficient propagation distance. They increase with increasing outer scale for 3.6<<4, and with decreasing inner scale. Only at a shorter propagation distance is the effect of turbulence on the beam-width spreading and M ²-factor negligible. The results are interpreted physically.

Keywords:

• non-Kolmogorov turbulence
• elegant Hermite–Gaussian (EHG) beam
• beam-width spreading
• angular spread
• M ²-factor

Acknowledgements

This work is supported by Science Foundation of Sichuan Provincial Education Department under Grant No. 10ZC032, and the Natural Science Foundation of Yibin University under Grant No. 2010B14.