Abstract

The mutual coherence function of a finite laser beam propagating through a random medium is calculated from the extended Huygens principle. Formulas are presented for the transverse coherence from an arbitrarily truncated focused Gaussian beam. Expressions are derived for a modified Kolmogorov spectrum for the refractive index fluctuations and for the case of nonuniform turbulence. The formalism is used to derive the conditions under which instantaneous reciprocity exists between a transmitter and receiver in a coherent detection system. It is also shown that a maximum useful transmitter (as well as receiver) diameter exists for computing the average normalized signal-to-noise ratio of this system. This maximum dimension is the smaller of the turbulence-induced coherence length and a Fresnel zone.

© 1973 Optical Society of America

Mutual Coherence Function of a Finite Cross Section Optical Beam Propagating in a Turbulent Medium

H. T. Yura
Appl. Opt. 11(6) 1399-1406 (1972)

Short-term average optical-beam spread in a turbulent medium

H. T. Yura
J. Opt. Soc. Am. 63(5) 567-572 (1973)

Propagation of Finite Cross-Section Laser Beams in Sea Water

H. T. Yura
Appl. Opt. 12(1) 108-115 (1973)

Optical Heterodyne Signal Power Obtained from Finite Sized Sources of Radiation

H. T. Yura
Appl. Opt. 13(1) 150-157 (1974)

Propagation of a Finite Optical Beam in an Inhomogeneous Medium

R. F. Lutomirski and H. T. Yura
Appl. Opt. 10(7) 1652-1658 (1971)