Fig. 7From: Spectral composition of low-coherence interferograms at high numerical aperturesProfiles of a rectangular grating standard (RS-N with 6 μm period manufactured by Simetrics) obtained by a Mirau interferometer with NA = 0.55 using (a) red and (b) blue LED illumination with center wavelength of 628 nm and 444 nm, respectively, (c) and (d) corresponding signal spectra for pixels related to edges and plateausBack to article page