Wavelength Dependence of Laser-Beam Scintillation*

Non-degenerate wavelength computational ghost imaging with thermal light

“…Fig.5 shows that the spatial resolution of ghost image obtained by 635 nm (Fig.5(d)) is better than that of 532 nm (Fig.5(c)). The reason for this phenomenon is that strong turbulence has less effect on long wavelength laser than that on short wavelength laser [26]. Further studies have shown that this conclusion applies to all types of ghost imaging.…”

Analysis of a Long-Distance System Measuring the Concentration of Atmospheric Gaseous Pollutants

“…Reviews of the literature dealing with this scintillation problem are given in (2] and [3]. Experimental results from [4] about CO2 -laser radiation propagation are used in this analysis.…”

“…A simple model based on measurements by Fitzmaurice et al [4] is used here, together with theoretical results concerning the propagation range dependence of the variance and the correlation time of the log-amplitude normalized intensity variation. Fitzmaurice et al determined the variance of the normalized intensity variations a2, the temporal power spectrum P(f), and the autocorrelation function R(r) of the intensity fluctuations at 0.632 and 10.6 ,um using point detectors.…”

“…Measurements by Chu [5] confirm some of their results. In [4], the autocorrelation function R(r) is approximated by an exponential function, i.e., R(r) = C exp (=C)…”

“…Numeric values of these parameters for CO2-laser radiation propagating 1 km are a2 = 2.8 X 10-2 and tc = 1.5 X 10-2 second, according to [4] (note that the variance value in [4] is multipled by four). Using the propagation path dependence from (9) gives a2 = 1-exp (9 X 10-8(r)11 / 6), geneities moving across the propagation path.…”