Temporal van Cittert-Zernike Theorem and Its Application to the Measurement of Chromatic Dispersion
01 January 2004
A time-domain equivalent of the van Cittert-Zernike theorem is formulated. Thre two-time correlation function of an incoherent source after temporal gating and chromatic dispersion is derived. Partial temporal coherence is established, identically to the establishment of partial spatial coherence in the far field for a spatially incoherent source after propagation through an aperture and diffraction. It is shown both theoretically and experimentally that the temporal degree of coherence of the source is related to the modulus of the Fourier transform of the temporal transmission of the gate. The derivation of the two-time correlation function is applied to the measurement of chromatic dispersion using a time-gated incoherent source.