Unique interpretation of Talbot Bands and Fourier domain white light interferometry

Abstract

A theoretical model is developed to interpret the output of the diffraction grating spectrometer used to analyze the channelled spectrum produced by a low coherence interferometer set-up. This model leads to an unique interpretation which covers both cases (i) of Talbot bands and (ii) of a Michelson interferometer used in most spectral interferometry set-ups for sensing as well as for Fourier domain optical coherence tomography (FDOCT). Explanation of Talbot bands visibility as well as the decay of sensitivity with depth, characteristic for FDOCT, is explained by considering the extension of the two wavetrains diffracted by the diffraction grating in the spectrometer.

Towards a research pole in photonics in Western Romania

“…Expertise was extended to dentistry [47], to imaging of basal cell carcinoma and to art conservation [50]. Other current research focuses on a novel solutions to reject the effect of mirror terms in spectrometer based OCT [51], to eliminate the speckle in OCT, to perform 3D imaging using multiple paths configurations [52,53], on coherence gated wavefront sensors [54] and on speeding up the acquisition based on graphics cards [55].…”

Two-grating Talbot bands spectral-domain interferometer

“…The effects of several geometrical parameters on the visibility performance versus optical path difference between the two arm lengths of the interferometer are evaluated. © [1][2][3][4] represent a particular case of modulation of the channeled spectrum at the output of an interferometer illuminated by a broadband optical source. This modulation takes place for only one sign of the optical path difference (OPD) in the interferometer.…”

“…In optical coherence tomography (OCT) applications, the inability to make distinction between the two signs of the OPD leads to superposition of cross section images due to the positive and the negative OPD. This is known as the problem of mirror terms [2,5]. Several mirror term removal methods have been described in the literature, such as sequential phase-shifting interferometry [6], phase shifting using a 3x3 splitter [7], resorting to phase modulation [8]or dispersion [9] to restore the full range and address the ambiguity of the OPD sign.…”

“…Previous studies of Talbot bands [2] have shown that the dif- [11]. The footprints are considered for simplicity as top hats with widths S = 4 mm.…”

“…Previous reports on Talbot bands [2,12] developed the explanation of the visibility curve versus OPD as determined by the product of C (shown in Fig. 1 for three values of gap g) with a sinc factor.…”