Application of the van Cittert-Zernike Theorem in the Heterodynreceiving of Optical and IR Frequencies

摘要

The derivation of the heterodyn current with the assumption that waves with various phase differences fall upon a detector device is addressed. The derived results are related to the degree of coherence, which indicate these phase differences. From this and the application of the van Cittert-Zernike theorem the diameter of the source of radiation can be calculated with the required degree of coherence in the position of the detector.