Propagation of Bessel-Gaussian Shell-model beam through a jet engine exhaust turbulence

• Published in: Optical and quantum electronics 2022, Vol.54 (6), Article 332
• Main Authors: Nabil, H., Balhamri, A., Belafhal, A.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Coherence; Computer Communication Networks; Density; Distribution functions; Electrical Engineering; Gaussian beams (optics); Jet engines; Lasers; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Propagation; Turbulence; Turbulent jets; Wigner distribution
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-022-03743-3

In this work, the effects of a turbulent jet engine exhaust on the propagation properties of a partially coherent Bessel-Gaussian Schell-model beam (BGSMB) of all orders are investigated and developed. Theoretical expressions of the cross spectral density (CSD) function, spectral density, degree of coherence and root-mean-square (r.m.s) beam width are derived with the help of the Huygens-Fresnel principle and the second-order moments of the Wigner distribution function. Based on our elaborated formulae, the influences of the initial beam parameters and the strength of turbulence on the behavior of the considered beam are numerically analyzed. It is shown that, by changing the source coherence width, the partially coherent BGSMB takes different shapes. For high source coherence width, the spectral density takes an elliptical shape, upon propagation distances; when the source coherence width decreasing the beam takes a well-like profile. If the source coherence width is small, the beam evolves into an dark hollow at short propagation distance. Also, our main found results, in the case of odd mode, the beam splits into two beams spot during its propagation. Compared with Gaussian Schell-model beam (GSMB), it has higher spreads and less influenced by the strength of turbulence if the source coherence width is lower. Consequently, this result will be useful for enhances the system performance.