Influence of longitudinal spatial coherence on the signal of a scanning interferometer

Abstract

The physical conditions for observing the longitudinal spatial coherence of light of an extended thermal source in interference experiments are defined. For experimental verification of these conditions a Michelson interferometer with a longitudinal scanning mirror was used. The influence of the longitudinal spatial coherence of thermal light on a fringe envelope is demonstrated experimentally.

Spatial and temporal coherence effects in interference microscopy and full‐field optical coherence tomography

“…For biomedical optics applications the use of infrared light is preferable as it penetrates deeper in tissue [90], which then requires the development of highresolution infrared cameras. For frequency-domain FF-OCT operation [91], tunable sources and fs sources that can reveal the spectral interference images in a short time will be helpful.Finally, it should be mentioned that spatial coherence effects in other related fields such as interferometry in general, holography, surface profiling and other applications has been an active field of research during the last two decades [92][93][94][95][96][97]. The group at Saratov University has been studying longitudinal spatial coherence extensively [98][99][100][101] …”

Объем Когерентности Оптического Волнового Поля С Широкими Частотным И Угловым Спектрами

“…Однако длина L c продольной когерентности оптиче-ского волнового поля, как показано в [25][26][27][28][29][30]33,34], при определенных условиях, определяемых соотношением параметров частотного и углового спектров, может огра-ничиваться не шириной частотного спектра поля ω, а шириной его углового спектра 2θ:…”

“…В работах [20][21][22][23][24][25][26][27][28][29][30][31][32] теоретически и экспериментально установлено, что длина продольной когерентности вол-нового поля может ограничиваться не только шириной его частотного спектра, но и шириной его углового спектра или совместно и шириной частотного, и шири-ной углового спектров поля [33,34]. Более того, длина поперечной когерентности также оказывается зависимой от ширины частотного спектра при достаточно большой его ширине [34,35].…”

Synthetic spatial coherence function for optical tomography and profilometry: influence of the observation condition

“…If we set a certain value of γ i (i=1, ..., N) for longitudinal coherence scan, then the corresponding height ∆ i (i=1, ..., N) can be determined from the matching condition of Eq. (10). From these values, β 1i for the maximum value of I i (x, y) can be easily found out by the straightforward calculations.…”

“…Besides solving the dispersion problem, the proposed technique enabled longitudinal coherence scan and phase shift without mechanical movement of a mirror for changing the optical path difference. Several papers have been published on spatial coherence control [4][5][6][7][8][9][10] , but in most of the papers [6][7] the discussions were centered on how the coherence function is related to the distance and the tilt between the object and the reference mirror. From the theory of fringe localization, one can expect that even for an identical optical system with the same distance and tilt between the object and the reference mirror, the observed fringe contrast will be significantly different depending on the location where the observation lens is focused.…”