Effectiveness of phase-conjugation systems in turbulent atmosphere

The performance of phase conjugation adaptive systems for ranging and probing is analyzed, taking into account turbulence of the real atmosphere. Specifically, a system is considered which reverses only the front of the incident wave, and builds up the reflected wave to an amplitude not dependent on that of the incident wave. The mean field intensity and the mean energy of reflected waves are calculated in the Gaussian approximation, with an attendant evaluation of their statistical characteristics, assuming that a spherical wave from a point source is reflected by such a phase conjugation system at a given distance L away and that the amplitude of the reflected wave is known. General relations are established and applied to reflectors with small aperture and correspondingly strong diffraction, to reflectors with apertures within the intermediate range, and to reflectors with large apertures with compensation and strong refraction. In both large and small apertures the mean intensity is equal to the intensity at the center, owing to the particular mechanism operating in each case.