Effects of Turbulence Instabilities on Laser Propagation
Quarterly progress rept. no. 3, 9 Dec 1971-8 Mar 1972
RCA LABS PRINCETON NJ
Pagination or Media Count:
Several statistics of the focal spot of a focussed laser beam in turbulent air are computed. The average area is recomputed for horizontal propagation, and corrected graphs are presented. Comparison to the half-power area is made, and it is concluded that the irradiance-weighted radius variance is a slightly better criterion, although the differences are small. The calculations are extended to slant paths. The power spectrum of the area scintillation is shown to be proportional to that of angle of arrival of a ray. It is computed for frozen flow and for random flow with zero mean velocity. Both spectra are initially flat, then decay as f to the minus 23 power. A composite formula is suggested for the general case.
- Lasers and Masers