Kaynak anizotropisinin serbest uzay iletişimde stokastik elektromanyetik ışınların yoğunluk korelasyonları üzerindeki etkisi

Öz

Anizotropik çapraz spektral yoğunluk matrislerine sahip kaynaklar tarafından üretilen stokastik elektromanyetik ışınların yoğunluk değişimleri arasındaki korelasyonlar araştırıldı. Geçtiğimiz yıllarda tanıtılan spektral çapraz polarizasyon derecesi, spektral tutarlılık derecesi ve elektromanyetik kaynakların yayılma üzerine yoğunluk dalgalanmaları, kaynağı bir anizotropik ışın olarak ele alarak analiz edildi. Boş uzayda ilerleyen ve boyuna ve enine yönlere uzanan bir anizotropik elektromanyetik Gauss Schell ışınının çapraz spektral yoğunluk matrisi için analitik bir formül verilmiştir. Analiz, aynı kaynak parametrelerine sahip iki ışının çapraz polarizasyonunun, anizotropi oranı α'ya bağlı olarak yayılma sırasında artabileceğini veya azalabileceğini göstermektedir. Işın anizotropisinin kısmen uyumlu kaynakları modellemek için uygun yöntemlerden biri olabileceğini göstermek için sayısal sonuçlar sunulmuştur.

Anahtar Kelimeler

• Optik komünikasyon
• Kısmi tutarlılık
• Fiziksel optik
• Elektromanyetik dalgalar

Effect of source anisotropy on the intensity correlations of stochastic electromagnetic beams in free space communications

Abstract

Correlations between stochastic electromagnetic beams' intensity variations which are produced by sources with anisotropic cross-spectral density matrices are explored. Recently introduced spectral degree of cross-polarization, spectral degree of coherence, and the intensity fluctuations of electromagnetic sources are analyzed upon propagation by considering the source as an anisotropic beam. An analytical formula is given for the cross-spectral density matrix of an anisotropic electromagnetic Gaussian Schell beam moving across free space and extended to longitudinal and transverse directions. The analysis shows that the cross-polarization of two beams having same source parameters might increase or decrease on propagation depending on the anisotropy ratio α. Numerical results are presented to show that the beam anisotropy might be one of the convenient methods for modeling partially coherent sources.

Keywords

• Optical communications
• Partial coherence
• Physical optics
• Electromagnetic waves

Kaynakça

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