Optimized spectral bandwidth in high angular resolution imaging effect of a finite spatial-coherence outer scale

In the case of high angular resolution techniques (speckle interferometry, long baseline Michelson interferometry), one has studied how varies the signal-to-noise ratio (SNR) in terms of the spectral bandwidth . For values of varying from 0 up to 100 nanometers, it is shown that the SNR, contrary to the predictions, has no maximum value. In addition, in the case of the high frequency approximation, the effects of a finite spatial-coherence outer scale, the influence of the turbulence model used and of the optical energy of the turbulence on the optimal spectral bandwidth have been analyzed and discussed.